Instead of scattered PDFs and photocopied notes, we have organized this article exactly the way a workshop viva actually flows: shop by shop, machine by machine. Bookmark this page — at 6000+ words, it doubles as a one-stop revision sheet for your entire semester of workshop technology.
Every trade below — fitting, carpentry, welding, smithy, foundry, sheet metal, and the full machine shop — is treated as its own mini-viva, complete with the tool names, working principles, and safety points examiners return to year after year. Whether your exam is next week or next month, working through these workshop viva questions and answers section by section is the closest thing to a real mock viva you will find online.
📑 Quick Navigation
- Basic Workshop Technology
- Fitting Workshop
- Carpentry Workshop
- Welding Workshop
- Smithy Workshop
- Foundry Workshop
- Sheet Metal Workshop
- Machine Shop
- Lathe Machine
- Drilling Machine
- Shaper & Planer Machine
- Milling Machine
- Grinding Machine
- Measuring Instruments
- Workshop Tools & Equipment
- Cutting Tools & Machining Operations
- Workshop Safety Rules
- Personal Protective Equipment
- Engineering Materials
- Manufacturing Processes
- Workshop Practical Exam Tips
- Diploma & B.Tech Level Questions
- Frequently Asked Questions
- How to Prepare
- Cycle 1 & Cycle 2 Lab Viva Q&A
- Tinsmithy Viva Q&A
- House Wiring Viva Q&A
- Power Tools Viva Q&A
1. Workshop Viva Questions and Answers: Cycle 1 and Cycle 2
Many colleges split first-year workshop practice into two lab cycles, each with its own viva. Below, workshop viva questions and answers are presented with respect to Cycle 1 and Cycle 2. Cycle 1 consists of four trades — Fitting, Welding, Foundry, and Machine Shop — while Cycle 2 also consists of four trades — Carpentry, Tinsmithy, House Wiring, and Power Tools. The viva questions and answers for both Cycle 1 and Cycle 2 are provided below, trade by trade, so you can revise exactly the way your lab manual is structured.
🔧 Cycle 1 — Fitting
Q1. What is fitting?
Fitting is a manufacturing process of shaping and assembling metal parts using hand tools to achieve the desired size and finish.
Q2. What is the sequence of operations performed in the fitting shop?
Marking → Cutting → Filing → Drilling → Reaming → Tapping → Finishing → Inspection.
Q3. What are the work holding tools used in fitting?
Bench vice, hand vice, machine vice, clamps, V-blocks, and angle plates.
Q4. What are the measuring and marking tools used in the fitting shop?
Steel rule, Vernier caliper, micrometer, try-square, scriber, divider, surface plate, and marking gauge.
Q5. What are the cutting tools used in fitting?
Hacksaw, chisel, files, drills, reamers, taps, and dies.
Q6. What are the finishing tools used in fitting?
Files (smooth, bastard), emery paper, and polishing tools.
Q7. What are the striking tools used in fitting?
Ball peen hammer, cross peen hammer, and mallet.
Q8. What is the use of a try-square?
It is used to check the squareness (90° angle) and to mark right angles on a workpiece.
Q9. What is the difference between a dot punch and a center punch?
A dot punch is used for light marking with a small indentation, while a center punch makes a deeper mark to guide drilling.
Q10. What are the methods of filing?
Straight filing, cross filing, draw filing, and diagonal filing.
Q11. What safety precautions should be taken in the fitting shop?
Use proper tools, ensure tight clamping of the workpiece, wear goggles, avoid excessive force, and keep tools in good condition.
🔥 Cycle 1 — Welding
Q1. What is welding?
Welding is a process of joining two or more metal parts by heating them to a suitable temperature with or without pressure and filler material.
Q2. Name a few welding processes.
Arc welding, gas welding, TIG welding, MIG welding, and spot welding.
Q3. What are the essential tools and equipment used in welding?
Welding machine, electrodes, welding cables, electrode holder, chipping hammer, wire brush, safety helmet, and gloves.
Q4. What safety precautions are followed in welding?
Wear a welding helmet and gloves, ensure proper ventilation, avoid direct exposure to arc light, and keep flammable materials away.
Q5. What are the types of weld joints?
Butt joint, lap joint, corner joint, edge joint, and T-joint.
Q6. What materials are required for the welding process?
Base metal, filler rod/electrode, flux, and shielding gas (in some processes).
Q7. What is the sequence of operations in the welding process?
Preparation of joint → Cleaning → Setting → Welding → Cooling → Inspection → Finishing.
Q8. What is the difference between arc welding and gas welding?
Arc welding uses an electric arc as the heat source and is faster, while gas welding uses a flame (oxygen + acetylene), is slower, but gives better control.
Q9. Name common welding defects.
Porosity, cracks, slag inclusion, undercut, and incomplete fusion.
🏭 Cycle 1 — Foundry (Sand Moulding)
Q1. What is a foundry?
A foundry is a place where metal casting is done by melting metal and pouring it into moulds.
Q2. Explain the foundry / sand moulding process.
Pattern preparation → Mould making → Core making → Melting → Pouring → Cooling → Shakeout → Cleaning → Inspection.
Q3. What tools and equipment are used in foundry work?
Flask, trowel, riddle, rammer, sprue pin, vent wire, and ladle.
Q4. What safety precautions should be taken in foundry work?
Wear heat-resistant PPE, avoid moisture in moulds, handle molten metal carefully, and maintain a safe distance.
Q5. What are the properties of moulding sand?
Permeability, strength, plasticity, refractoriness, adhesiveness, and cohesiveness.
Q6. What are the kinds of moulding sand?
Green sand, dry sand, loam sand, facing sand, and core sand.
Q7. What is a pattern, and what are its types?
A pattern is a replica of the casting used to prepare the mould cavity; types include solid pattern, split pattern, match plate pattern, and sweep pattern.
Q8. What is the use of a sprue and a riser?
A sprue allows molten metal to enter the mould, while a riser supplies extra metal to compensate for shrinkage.
Q9. What is the use of a core in the sand moulding process?
A core is used to create internal cavities or hollow sections in a casting.
Q10. What is a mould cavity?
It is the hollow space formed in the mould that takes the shape of the final casting.
Q11. What is the difference between a solid pattern and a split pattern?
A solid pattern is made in one piece, while a split pattern is divided into two halves for easy removal from the mould.
Q12. What is the use of a strike-off bar in the moulding process?
It is used to remove excess sand and level the mould surface.
Q13. What is the use of parting sand?
It prevents sticking between the mould halves and the pattern.
Q14. How is a pattern different from a casting?
A pattern is the model used to make the mould, while the casting is the final metal product obtained after solidification.
⚙️ Cycle 1 — Machine Shop
Q1. What is a lathe machine and what are its uses?
A lathe machine rotates the workpiece against a cutting tool to perform operations like turning, facing, drilling, and threading.
Q2. What are the main parts of a lathe machine?
Bed, headstock, tailstock, carriage, spindle, chuck, and tool post.
Q3. What is the difference between facing and turning?
Facing produces a flat surface at the end of the workpiece, while turning reduces the diameter along its length.
Q4. What is the purpose of a chuck, and what are its types?
A chuck holds the workpiece; common types include the three-jaw chuck, four-jaw chuck, and collet chuck.
Q5. What is the difference between turning, taper turning, and step turning?
Turning produces a uniform diameter, taper turning produces a conical shape, and step turning produces different diameters in steps along the same workpiece.
Q6. What safety precautions should be taken in the machine shop?
Wear proper clothing, avoid loose items, ensure proper clamping, keep hands away from rotating parts, and follow instructions carefully.
🪚 Cycle 2 — Carpentry
Q1. What are the applications of carpentry?
Carpentry is used for making furniture, doors, windows, roofs, cabinets, wooden structures, and interior decorations in buildings.
Q2. What are the types of joints used in carpentry?
Common joints include the butt joint, lap joint, mortise and tenon joint, dovetail joint, bridle joint, and tongue and groove joint.
Q3. What measuring tools are used in carpentry?
Steel rule, measuring tape, try square, calipers, and folding rule.
Q4. What marking tools are used in carpentry?
Marking gauge, pencil, scriber, try square, and marking knife.
Q5. What finishing tools are used in carpentry?
Plane, sandpaper, scraper, file, and polishing tools.
Q6. What cutting tools are used in carpentry?
Hand saw, chisel, plane cutter, and circular saw.
Q7. What types of files are used in carpentry?
Flat file, round file, half-round file, and rasp file.
Q8. What types of chisels are used in carpentry?
Firmer chisel, bevel edge chisel, mortise chisel, and paring chisel.
Q9. What safety precautions are taken in carpentry?
Wear safety goggles, keep tools sharp and clean, use the proper tool for the job, maintain correct posture, and keep the workplace clean.
Q10. Which hammer is used for extracting nails from wood?
A claw hammer is used to extract nails from wood.
🛠️ Cycle 2 — Tinsmithy
Q1. How can you measure the thickness of a galvanized iron (GI) sheet?
Thickness is measured using a micrometer screw gauge or a Vernier caliper.
Q2. What cutting tools are used in tinsmithy?
Snips, shears, hacksaw, and chisels.
Q3. What forming/shaping tools are used in tinsmithy?
Stakes, hammers, mallets, and rollers.
Q4. What striking tools are used in tinsmithy?
Ball peen hammer, mallet, and riveting hammer.
Q5. What marking tools are used in tinsmithy?
Scriber, divider, try square, and steel rule.
Q6. What measuring tools are used in tinsmithy?
Steel rule, calipers, Vernier caliper, and micrometer.
Q7. What are the types of snips?
Straight snips, left-hand snips, right-hand snips, and curved snips.
Q8. What is meant by "development of a surface" in tinsmithy?
It is the process of unfolding or laying out a 3D object into a flat pattern on a galvanized sheet before it is cut and formed.
🔌 Cycle 2 — Power Tools
Q1. How are power tools different from conventional tools?
Power tools operate using electricity or batteries and require less manual effort, whereas conventional tools are manually operated and require more physical effort.
Q2. Name a few power tools.
Electric drill, angle grinder, circular saw, jigsaw, and power sander.
Q3. What are the applications of power tools in household and industrial settings?
In households, they are used for drilling, cutting, and repairs; in industries, they are used for manufacturing, construction, and heavy-duty operations.
💡 Cycle 2 — House Wiring
Q1. What is the difference between series and parallel connection?
In a series connection, components are connected end-to-end and the same current flows through all of them; in a parallel connection, components are connected across the same voltage and the current divides among them.
Q2. What types of wires are used in electrical wiring?
PVC insulated wires, VIR wires, TRS cables, and flexible wires.
Q3. What is the difference between a fuse and a circuit breaker?
A fuse melts and breaks the circuit when excess current flows, while a circuit breaker automatically trips and can be reset.
Q4. What do symbols in electrical and electronic systems represent?
They represent components such as resistors, capacitors, diodes, switches, batteries, and ground connections in circuit diagrams.
Q5. What is earthing?
Earthing is the process of connecting electrical equipment to the ground to prevent electric shock and ensure safety.
Q6. What are the types of fuses?
Rewirable fuse, cartridge fuse, HRC fuse, and thermal fuse.
Q7. What are the applications of staircase wiring?
It is used to control a single light from two different locations, such as staircases and corridors.
Q8. What is the difference between a conductor and an insulator?
A conductor allows electric current to pass through it easily due to free electrons (e.g., copper, aluminum, silver), while an insulator does not allow current to pass through easily because it has very few or no free electrons (e.g., rubber, glass, plastic).
2. Basic Workshop Technology Viva Questions and Answers
Before diving into individual shops, examiners often warm up with general questions on workshop technology as a subject. These set the tone for the rest of your workshop viva questions and answers session.
Q1. What is workshop technology?
It is the branch of mechanical engineering that deals with the practical study of tools, machines, materials, and processes used to convert raw material into a finished, usable product.
Q2. Why do engineering students study workshop practice?
It builds hands-on familiarity with tools and machines, teaches dimensional accuracy, develops safety awareness, and bridges the gap between theoretical design and real manufacturing.
Q3. Name the major trades/shops covered under workshop practice.
Fitting, carpentry, welding, smithy (forging), foundry, sheet metal, and the machine shop (lathe, drilling, shaper, milling, grinding).
Q4. What is the difference between a "process" and an "operation" in a workshop?
A process is the overall method of changing raw material into a product (e.g., casting), while an operation is a single step within that process (e.g., pouring molten metal).
Q5. What is tolerance in engineering?
Tolerance is the permissible variation in a dimension — the difference between the maximum and minimum acceptable limits for a part to still function correctly.
Q6. What is meant by "workmanship"?
Workmanship refers to the skill and quality with which a job is executed, judged by accuracy, finish, and adherence to specified dimensions.
⚡ Quick Reference: What Examiners Check in Every Shop
Before the shop-wise breakdown, here is a fast cheat-sheet many students revise the morning of the exam. Use it as a final scan of your workshop viva questions and answers preparation.
| Shop | Examiner's #1 Focus | Most-Asked Question Type |
|---|---|---|
| Fitting | Tool names & measuring accuracy | "Identify this tool and its use." |
| Carpentry | Joint types & timber seasoning | "Name this joint." |
| Welding | Process selection & defects | "Why did this weld fail?" |
| Smithy | Forging temperature & operations | "What operation is this?" |
| Foundry | Pattern allowances & defects | "Name this casting defect." |
| Sheet Metal | Bending allowance & die function | "What is spring-back?" |
| Machine Shop | Machine parts & safe operation | "Show me how you would set this up." |
3. Fitting Workshop Viva Q&A
The fitting shop is usually the very first place students pick up a file, so examiners test both tool names and technique here.
Q1. What is fitting?
Fitting is the process of assembling and finishing components to the required shape and size using hand tools like files, hacksaws, chisels, and scrapers.
Q2. What is a bench vice used for?
A bench vice holds the workpiece firmly on the workbench so that filing, sawing, or chiseling can be performed safely and accurately.
Q3. Name the common types of files by their cut.
Single-cut, double-cut, rasp-cut, and curved-cut files, each suited to different materials and finishing requirements.
Q4. What is the difference between a scriber and a punch?
A scriber marks fine layout lines on a workpiece, while a punch (center or prick punch) creates a small indentation to locate a drilling point or make the line permanent.
Q5. What is a surface plate used for?
It provides a perfectly flat reference surface for marking out, checking flatness, and taking accurate height measurements.
Q6. What angle is a cold chisel typically ground to?
A cold chisel cutting edge is usually ground between 60° and 70° depending on the hardness of the material being cut.
4. Carpentry Workshop Viva Q&A
Q1. What is carpentry?
Carpentry is the trade of cutting, shaping, and joining wood to make patterns, furniture, and structural components.
Q2. Name common carpentry hand tools.
Jack plane, tenon saw, rip saw, chisel, mallet, marking gauge, try square, and claw hammer.
Q3. What is a mortise and tenon joint?
A woodworking joint where a projecting tenon on one piece fits into a matching mortise (slot) on another, commonly used in furniture framing.
Q4. Why is seasoning of timber necessary?
Seasoning reduces the moisture content of wood, preventing shrinkage, warping, and fungal decay after the wood is used in a product.
Q5. What is the function of a marking gauge?
It scribes a line parallel to an edge or end of a piece of timber to guide sawing or planing.
Q6. What is the purpose of a smoothing plane?
A smoothing plane removes thin shavings from a wooden surface to achieve a fine, flat finish after the wood has been roughly shaped.
Q7. Why is a try square used in carpentry rather than an engineer's square only?
A carpenter's try square is designed with a wooden or heavier metal stock suited to checking right angles on timber, which resists damage from wood surfaces better during layout work.
5. Welding Workshop Viva Q&A
Welding-related workshop viva questions and answers are asked in almost every practical exam because the process combines metallurgy, heat, and skill.
Q1. What is welding?
Welding is a fabrication process that joins two materials, usually metals, by melting the parts and adding a filler material to form a strong, permanent bond.
Q2. Differentiate arc welding and gas welding.
Arc welding uses an electric arc between an electrode and the workpiece to generate heat, while gas welding uses the heat of a burning fuel gas (like acetylene) mixed with oxygen.
Q3. What is the function of flux in welding?
Flux shields the molten weld pool from atmospheric oxygen and nitrogen, preventing oxidation and porosity in the weld.
Q4. What causes a weld to have blowholes?
Trapped gas due to moisture, contamination, or excessive welding speed causes blowholes; using dry electrodes and correct speed prevents them.
Q5. What is spot welding?
A resistance welding process where overlapping metal sheets are joined at localized points using heat generated by resistance to electric current under pressure.
Q6. Why is a leather apron and face shield mandatory during welding?
They protect the welder from sparks, UV/IR radiation ("arc eye"), and molten spatter that can cause burns.
6. Smithy Workshop Viva Q&A
Q1. What is smithy or forging?
Smithy is the process of shaping heated metal, usually by hammering, to produce components with improved grain structure and mechanical strength.
Q2. What is a forging temperature range for mild steel?
Mild steel is typically forged between 1100°C and 1250°C, glowing bright yellow-orange, and forging must stop above the lower critical temperature.
Q3. What is the function of an anvil?
The anvil is a heavy steel block that supports the hot workpiece and provides a hard surface against which the blacksmith hammers it into shape.
Q4. What is upsetting in forging?
Upsetting is the operation of increasing the cross-sectional area of a bar at the expense of its length by hammering along its axis.
Q5. What is the difference between forging and casting?
Forging shapes solid metal through plastic deformation, refining grain flow, while casting shapes metal by pouring it in molten form into a mould.
Q6. What is the function of tongs in smithy work?
Tongs are used to grip and hold red-hot metal safely while it is moved between the furnace and the anvil for hammering.
Q7. What is drawing down in forging?
Drawing down is the operation of reducing the cross-section of a bar while increasing its length, the opposite of upsetting.
7. Foundry Workshop Viva Q&A
Q1. What is a foundry/casting process?
Casting is a manufacturing process in which molten metal is poured into a mould cavity and allowed to solidify into the desired shape.
Q2. What is a pattern in foundry work?
A pattern is a replica of the part to be cast, used to create the mould cavity in the sand; it is slightly oversized to allow for shrinkage.
Q3. What is meant by shrinkage allowance?
It is the extra dimension added to a pattern to compensate for the contraction of metal as it cools from liquid to solid state.
Q4. What is a riser and why is it needed?
A riser is a reservoir of molten metal connected to the casting that feeds liquid metal into the mould as it shrinks, preventing shrinkage cavities.
Q5. What is the difference between green sand and dry sand moulding?
Green sand moulding uses moist sand and is used directly, while dry sand moulds are baked to remove moisture for higher strength and better surface finish.
Q6. Name common casting defects.
Blowholes, shrinkage cavities, sand inclusion, misrun, cold shut, and porosity are the most frequently asked casting defects in a viva.
8. Sheet Metal Workshop Viva Q&A
Q1. What is sheet metal work?
It is the shaping of thin, flat metal sheets into components such as ducts, containers, and enclosures through cutting, bending, and joining.
Q2. What is the function of a snip (tin snip)?
A snip is a hand tool used to cut thin sheet metal along straight or curved lines, similar to heavy-duty scissors.
Q3. What is a "seam" in sheet metal work?
A seam is a joint formed by folding and interlocking the edges of two sheet metal pieces, commonly used before soldering for extra strength.
Q4. What is bending allowance?
Bending allowance is the extra length of sheet metal that must be added along the neutral axis to accommodate the material stretched during bending.
Q5. What is a die in sheet metal press work?
A die is the female tool that, together with a matching punch, shears, bends, or forms the sheet metal into the desired shape under press force.
Q6. What is the difference between blanking and piercing?
Blanking cuts out a piece of sheet metal to be used as the final part (the cut-out piece is the product), while piercing punches a hole and the cut-out piece is the scrap.
Q7. What is spring-back in sheet metal bending?
Spring-back is the tendency of sheet metal to partially return toward its original shape after the bending force is released, so parts are often over-bent to compensate.
9. Machine Shop Viva Q&A
Q1. What is a machine shop?
A machine shop is a section of the workshop equipped with power-driven machine tools like lathes, drills, millers, and grinders used to remove material and achieve precise dimensions.
Q2. What is meant by "machining"?
Machining is a controlled material-removal process that shapes a workpiece by cutting away excess material using a cutting tool.
Q3. What is the difference between a conventional and a CNC machine?
A conventional machine is operated manually by a skilled worker, while a CNC (Computer Numerical Control) machine follows a programmed code to control tool movement automatically.
Q4. What is a jig, and how is it different from a fixture?
A jig both holds the workpiece and guides the cutting tool (e.g., drill jig), whereas a fixture only holds and locates the workpiece without guiding the tool.
Q5. What is meant by machinability?
Machinability is the ease with which a material can be cut, judged by tool life, surface finish, and power consumption during machining.
10. Lathe Machine Viva Q&A
The lathe machine section is one of the most heavily tested parts of any workshop viva questions and answers session, since almost every mechanical student performs turning practicals.
Q1. What is a lathe machine used for?
A lathe machine rotates a workpiece against a stationary cutting tool to perform turning, facing, threading, knurling, and boring operations.
Q2. Name the main parts of a lathe machine.
Bed, headstock, tailstock, carriage, cross-slide, compound rest, chuck, and lead screw are the primary parts examiners expect you to identify.
Q3. What is the difference between facing and turning?
Facing removes material from the end face of the workpiece to create a flat surface, while turning removes material from the outer diameter along its length.
Q4. What is the function of the tailstock?
The tailstock supports the free end of a long workpiece and holds tools like drills and centers to maintain alignment during machining.
Q5. What is cutting speed in a lathe?
Cutting speed is the speed at which the workpiece surface moves past the cutting tool, usually expressed in meters per minute.
Q6. What is knurling?
Knurling is a lathe operation that produces a textured, criss-cross pattern on a cylindrical surface to improve grip.
11. Drilling Machine Viva Q&A
Q1. What is a drilling machine used for?
A drilling machine produces cylindrical holes in a workpiece using a rotating cutting tool called a drill bit.
Q2. What is the difference between a pillar drill and a radial drilling machine?
A pillar (bench) drill is fixed and best for small workpieces, while a radial drilling machine has an adjustable arm that swings the drill head to reach large, heavy workpieces without repositioning them.
Q3. What is the point angle of a standard twist drill?
The standard point angle of a general-purpose twist drill is 118°, though harder materials may require a steeper angle.
Q4. What is reaming?
Reaming is a finishing operation performed after drilling to enlarge and true a hole to a precise diameter with a smooth surface finish.
Q5. What is counterboring used for?
Counterboring enlarges the top of a hole to a specific depth so that a bolt head or socket head screw sits flush with the surface.
12. Shaper and Planer Machine Viva Q&A
Q1. What is the working principle of a shaper machine?
A shaper produces flat surfaces by moving a single-point cutting tool back and forth (reciprocating) over a stationary workpiece.
Q2. What is the quick return mechanism?
It is a mechanism in shapers and planers that makes the tool's return (non-cutting) stroke faster than the cutting stroke, saving machining time.
Q3. How does a planer differ from a shaper?
In a shaper, the tool reciprocates while the workpiece is stationary; in a planer, the workpiece (table) reciprocates while the tool remains stationary — planers are used for much larger jobs.
Q4. What is the function of the clapper box in a shaper?
The clapper box allows the tool to lift slightly during the return stroke, preventing it from dragging and damaging the finished surface.
Q5. Name common operations performed on a shaper.
Producing flat horizontal, vertical, and angular surfaces, as well as cutting slots, grooves, and keyways.
13. Milling Machine Viva Q&A
Q1. What is a milling machine?
A milling machine uses a rotating multi-point cutter to remove material from a stationary or fed workpiece, producing flat surfaces, slots, gears, and complex profiles.
Q2. Differentiate up milling and down milling.
In up milling, the cutter rotates against the direction of feed; in down milling, the cutter rotates in the same direction as the feed, giving a better surface finish.
Q3. What is an arbor in milling?
An arbor is a shaft used to mount and drive the milling cutter on the machine spindle.
Q4. What is indexing in milling?
Indexing is the process of rotating the workpiece through a precise angle using a dividing head, used for cutting gears, splines, and flutes.
Q5. Name the two main types of milling machines by orientation.
Horizontal milling machines and vertical milling machines, classified by the orientation of the spindle relative to the table.
14. Grinding Machine Viva Q&A
Q1. What is grinding?
Grinding is a finishing operation that uses an abrasive wheel to remove a small amount of material and achieve a fine surface finish and tight dimensional accuracy.
Q2. What is a grinding wheel made of?
A grinding wheel consists of abrasive grains (like aluminum oxide or silicon carbide) held together by a bonding material such as vitrified or resinoid bond.
Q3. What is meant by "wheel dressing"?
Dressing removes dull grains and reshapes the wheel face to restore its cutting ability and true geometry.
Q4. What is the difference between cylindrical and surface grinding?
Cylindrical grinding finishes the outer or inner diameter of round workpieces, while surface grinding produces flat, precise surfaces on flat workpieces.
Q5. What does "grade" of a grinding wheel indicate?
The grade indicates the strength of the bond holding the abrasive grains — a "hard" wheel retains grains longer, while a "soft" wheel releases dull grains faster for self-sharpening.
15. Measuring Instruments Viva Q&A for Workshop Practice
No set of workshop viva questions and answers is complete without measuring instruments — examiners frequently hand you a vernier caliper and ask you to read it on the spot.
Q1. What is the least count of a standard vernier caliper?
The least count of a standard vernier caliper is typically 0.02 mm, calculated as the value of one main scale division divided by the number of vernier divisions.
Q2. What is a micrometer used for?
A micrometer measures small external or internal dimensions with very high precision, typically up to 0.01 mm, using a calibrated screw thread.
Q3. What is the difference between accuracy and precision?
Accuracy is how close a measurement is to the true value, while precision is how consistently repeated measurements agree with each other.
Q4. What is a try square used for?
A try square checks and marks right angles (90°) between two surfaces of a workpiece.
Q5. What is a dial gauge (dial indicator)?
A dial gauge measures small linear displacements or checks alignment and runout by converting a plunger's movement into a rotating needle reading.
Q6. What is a feeler gauge used for?
A feeler gauge measures small gaps or clearances between two mating surfaces using thin, precisely-sized blades.
Q7. What is a screw pitch gauge?
A screw pitch gauge quickly identifies the pitch (thread spacing) of a screw or bolt by matching its blades against the thread profile, without needing a separate calculation.
Q8. Why must measuring instruments be handled with clean, dry hands?
Moisture, oil, and dirt on the hands can corrode precision surfaces or introduce measurement error, so instruments like micrometers and vernier calipers should always be wiped clean before and after use.
16. Workshop Tools and Equipment Viva Q&A
Q1. What is the difference between a hand tool and a power tool?
A hand tool is operated manually using human effort, while a power tool is driven by an external energy source such as electricity or compressed air.
Q2. What is a hacksaw used for, and what does TPI mean?
A hacksaw cuts metal manually; TPI (Teeth Per Inch) indicates blade coarseness — a higher TPI is used for thinner materials and a lower TPI for thicker, softer materials.
Q3. What is the purpose of a spanner/wrench set?
Spanners and wrenches tighten or loosen nuts and bolts of various standard sizes without damaging their hexagonal heads.
Q4. Why should tools be stored in a shadow board or tool cabinet?
It keeps tools organized, prevents damage or loss, and lets supervisors instantly see if a tool is missing after a job.
Q5. What is a C-clamp used for?
A C-clamp temporarily holds or secures a workpiece to a table or fixture during marking, drilling, or welding.
17. Cutting Tools and Machining Operations Viva Q&A
Q1. What are the two main types of cutting tools by geometry?
Single-point cutting tools (used in lathes and shapers) and multi-point cutting tools (used in milling cutters, drills, and reamers).
Q2. What is tool rake angle?
Rake angle is the angle between the tool face and a reference plane, controlling how easily the chip flows off the tool and affecting cutting force.
Q3. What is non-traditional machining?
Non-traditional machining removes material using thermal, chemical, or electrical energy instead of direct mechanical cutting force — used for very hard or heat-sensitive materials.
Q4. Name three non-traditional machining processes.
Electrical Discharge Machining (EDM), Electrochemical Machining (ECM), and Laser Beam Machining (LBM) are commonly asked examples.
Q5. What is a coolant used for during machining?
Coolant reduces heat generated at the tool-workpiece interface, extends tool life, washes away chips, and improves surface finish.
Q6. What is chip formation, and what are the common types of chips?
Chip formation is the shearing and deformation of material ahead of the cutting tool; the three common types are continuous chips, discontinuous chips, and continuous chips with a built-up edge, depending on material ductility and cutting conditions.
18. Workshop Safety Rules Viva Q&A
Q1. Why are safety rules important in a workshop?
They prevent accidents, protect students and staff from injury, and ensure machines and tools are used correctly and responsibly.
Q2. What should you check before starting a machine?
Check that guards are in place, the work area is clear, the machine is properly lubricated, and no loose clothing or jewelry is being worn.
Q3. Why should loose clothing and long hair be avoided near rotating machines?
They can get caught in rotating spindles, chucks, or belts, causing severe injury.
Q4. What should you do immediately after a machining operation?
Switch off the machine, wait for it to come to a complete stop, and only then clean chips using a brush — never bare hands.
Q5. Why is horseplay strictly prohibited in the workshop?
Because sudden distractions near running machines, sharp tools, or hot metal can cause serious, often irreversible accidents.
Q6. What should be done in case of a minor cut or burn in the workshop?
Stop work immediately, inform the instructor, and use the first-aid kit for basic treatment before deciding if further medical attention is needed.
Q7. Why should fire extinguishers be clearly marked and unobstructed in a workshop?
Because welding, forging, and machining all involve heat or sparks, quick access to the correct type of extinguisher can prevent a small fire from spreading.
19. Personal Protective Equipment (PPE) Viva Q&A
Q1. What is PPE?
Personal Protective Equipment refers to wearable gear — such as goggles, gloves, and aprons — designed to protect the body from workshop hazards.
Q2. Why are safety goggles compulsory in a machine shop?
They protect the eyes from flying chips, sparks, and dust generated during turning, drilling, grinding, and welding.
Q3. Why should gloves not be worn while operating a lathe or drilling machine?
Gloves can get caught in rotating parts like the chuck or drill bit and pull the hand into the machine, so bare hands are actually safer on rotating equipment.
Q4. What footwear is recommended in a workshop?
Steel-toed safety shoes protect the feet from falling tools, hot metal, and sharp scrap.
Q5. Why is a welding helmet with a dark filter lens essential?
It shields the eyes and face from intense UV and infrared radiation produced by the welding arc, preventing "arc eye" and skin burns.
Q6. Why should ear protection be used near power hammers or pneumatic tools?
Prolonged exposure to loud machine noise can cause permanent hearing damage, so earplugs or earmuffs are recommended in high-noise sections of the workshop.
Q7. What is a dust mask/respirator used for in a workshop?
It filters out fine particles such as wood dust, metal grinding dust, and fumes, protecting the respiratory system during grinding, sanding, and welding operations.
20. Engineering Materials Viva Q&A for Workshop Practice
Q1. What is the difference between ferrous and non-ferrous metals?
Ferrous metals contain iron as the main constituent and are generally magnetic (e.g., steel, cast iron), while non-ferrous metals contain little or no iron and are typically non-magnetic (e.g., aluminum, copper, brass).
Q2. What is the difference between ductile and brittle materials?
Ductile materials can be drawn into wires and deform significantly before fracture (e.g., mild steel), while brittle materials fracture with little or no plastic deformation (e.g., cast iron, glass).
Q3. What is mild steel commonly used for in the workshop?
Mild steel, with low carbon content, is easy to machine, weld, and forge, making it the most common practice material in fitting, welding, and smithy shops.
Q4. What is annealing?
Annealing is a heat treatment process that heats a metal and cools it slowly to relieve internal stresses, soften it, and improve machinability.
Q5. What is a composite material?
A composite material is made from two or more distinct materials combined to achieve properties superior to either material alone, such as fiberglass or carbon-fiber composites.
Q6. Why is cast iron preferred for machine beds?
Cast iron has excellent compressive strength, damping capacity, and dimensional stability, which absorbs vibration and keeps machine beds rigid.
21. Manufacturing Processes Viva Q&A for Workshop
Q1. What are the primary classifications of manufacturing processes?
Casting, forming, machining, joining (welding), and finishing processes are the broad categories examiners expect you to list.
Q2. What is the difference between a forming process and a machining process?
Forming reshapes material by plastic deformation without removing material (e.g., rolling, forging), while machining removes material to achieve the final shape (e.g., turning, milling).
Q3. What is extrusion?
Extrusion forces heated or unheated material through a shaped die to produce long components with a constant cross-section, such as rods, tubes, and channels.
Q4. What is injection moulding used for?
Injection moulding melts plastic granules and injects them under pressure into a mould cavity, widely used to mass-produce plastic components.
Q5. What is rolling in metal forming?
Rolling passes a metal billet between rotating rolls to reduce its thickness and produce sheets, plates, and structural sections.
Q6. What is lean manufacturing?
Lean manufacturing is a production philosophy focused on minimizing waste — of time, material, and effort — while maximizing value to the customer.
22. Workshop Practical Exam Viva Q&A
Beyond shop-specific theory, examiners in a workshop practical exam evaluate how you carry out and explain your own job.
Q1. Explain the sequence of operations you followed to complete your job.
Be ready to narrate your job step-by-step — marking, cutting, filing/machining, checking dimensions, and finishing — in the exact order you performed them.
Q2. Why did you choose this particular tool for this operation?
Justify tool selection based on material hardness, required accuracy, surface finish, and the shape of the feature being produced.
Q3. What dimensional errors did you observe, and how would you correct them?
Identify the actual deviation from the drawing (oversize/undersize) and explain the corrective operation — such as an extra filing or machining pass — needed to fix it.
Q4. What safety precautions did you take while completing this job?
Mention specific precautions relevant to your job — PPE worn, machine guards checked, coolant used, or work area kept clear.
Q5. How would you scale up this job for mass production?
Discuss replacing manual operations with jigs, fixtures, or CNC programming to achieve repeatability and higher production rates.
23. Workshop Technology Viva Questions for Diploma and BTech Students
The depth of expected answers differs by level, which is worth knowing before you walk into the room.
| Aspect | Diploma Level | B.Tech Level |
|---|---|---|
| Focus | Tool names, basic operations, safety | Underlying theory, calculations, process selection |
| Typical Question | "Name the parts of a lathe machine." | "Derive the cutting speed formula and explain its effect on tool wear." |
| Depth Expected | Definitions and correct terminology | Reasoning, comparisons, and real-world application |
| Common Add-on | Identify the tool shown | Justify process/material selection for a given design |
Q1. (Diploma) What is the function of a chuck key?
It tightens or loosens the chuck jaws to grip or release the workpiece on a lathe or drilling machine.
Q2. (B.Tech) How does cutting speed affect tool life?
Higher cutting speeds generate more heat at the tool tip, accelerating wear via the Taylor tool-life equation (VT^n = C); optimum speed balances productivity against tool wear cost.
Q3. (B.Tech) Why is process planning important before machining a component?
It determines the most efficient sequence of operations, tool selection, and machine allocation, minimizing cost, time, and setup errors.
Q4. (Diploma) What is the difference between marking and measuring?
Marking transfers dimensions onto a workpiece as visible lines or punch marks, while measuring determines the actual numerical size of a feature using an instrument.
Q5. (B.Tech) How would you select an appropriate manufacturing process for a given component?
Consider production volume, material properties, required tolerance and surface finish, part geometry, and overall cost, then match these constraints to the most suitable process — casting for complex bulk shapes, machining for tight tolerances, or forming for high-strength, high-volume parts.
24. Frequently Asked Workshop Viva Questions for Practical Examinations
What are the most commonly repeated workshop viva questions and answers across all trades?
How many questions are typically asked in a workshop viva?
Do examiners deduct marks for not knowing exact numerical values (like angles or speeds)?
Is it necessary to memorize machine part names in the exact technical order?
Which workshop viva questions and answers carry the highest weightage in scoring?
Can I refer to notes during a workshop viva?
What should I do if I genuinely don't know the answer to a viva question?
Are workshop viva questions and answers the same across all engineering colleges?
25. How to Prepare for Workshop Viva Questions and Answers
1. Revise shop by shop, not randomly.
Go through fitting, carpentry, welding, smithy, foundry, sheet metal, and the machine shop in order, since examiners usually move through the syllabus sequentially.
2. Know your own job inside out.
You are far more likely to be questioned about the specific component you made than about a machine you never touched — be ready to explain every step you performed.
3. Practice identifying tools by sight, not just by name.
Examiners often hold up a tool and ask you to identify it and its use on the spot, so visual recognition matters as much as definitions.
4. Revise safety rules and PPE last, right before entering.
These are quick, confidence-building questions that are almost always asked and are easy to score full marks on if freshly revised.
5. Practice explaining answers out loud.
Speaking your answers to a friend or mirror improves clarity and reduces nervous stumbling during the actual viva.
Conclusion
Clearing a practical exam is rarely about knowing every textbook definition by heart — it is about walking in with a clear, confident grasp of the tools and machines you have actually used. This collection of Workshop Viva Questions and Answers was built to mirror exactly how a real viva unfolds: shop by shop, machine by machine, safety rule by safety rule. Revise the sections closest to your own practical work first, skim the rest for general awareness, and you will walk into your workshop viva with far more confidence than a night of last-minute cramming could ever give you. Good luck — and if this guide helped, bookmark it for your next semester's revision too.
Elements of Mechanical Engineering for III Year - Viva Questions and Short Answers
Basic Mechanical Engineering "Short Answers (SAQ/LAQ)"
Unit I:
- Describe the Carnot cycle with a PV Diagram. Why is it considered the most efficient cycle?
- Derivation of Otto cycle.
- Derivation of Diesel cycle.
- Derivations for the applications of First law of Thermodynamics - Const. Volume, Const. Pressure, Const. Temperature process. OR State and explain the First law of thermodynamics. How is it applied in constant volume and constant pressure process?
- Explain Zeroth law, First law and Second law of thermodynamics.
- Explain the working principle of 4-stroke SI Engine with neat sketch?
- Explain the working principle of 4-stroke CI Engine with neat sketch?
- Explain the working of Babcock and Wilcox boiler with neat sketch?
- Explain the working of Cochran boiler with neat sketch?
- Difference between Water tube and Fire Tube boilers.
- What are the components of Internal combustion engine?
- Explain about High pressure boilers?
- Explain the construction and working of a centrifugal pump. What are its main applications?
- Explain the working of Francis Turbine with neat sketch?
- Explain the working of Kaplan Turbine with neat sketch?
- Explain the working of Vapor compression refrigeration cycle with neat sketch?
- Explain the working of Vapor Absorption refrigeration cycle with neat sketch?
- Compare VAR with VCR?
- Explain the working of Bessemer converter with neat sketch.
- Explain the working of Electric Arc furnace with neat sketches.
- Explain 3 types of steel – low carbon steel, medium carbon and high carbon steel.
- Explain various types of composite materials.
- Explain the types and fabrication methods of composite material.
- Explain the types of cast iron with its characteristics.
- Explain non-ferrous materials – Aluminium & Copper.
- Explain the properties and types of stainless steel.
- What are the components of robot.
- Explain the working of CNC machine with a neat sketch.
- Explain the differences between CNC drilling, CNC milling, CNC boring, CNC turning operations and CNC tapping.
- Explain about NC and CNC turning centre.
- Explain the working of adaptive control with neat sketch.
Basic Mechanical Engineering "Viva Questions and Short Answers"
Unit I
1. List Energy Resources.
Energy resources are broadly classified as renewable and non-renewable.
Renewable sources include solar, wind, hydro, biomass, and geothermal energy.
Non-renewable sources include coal, petroleum, natural gas, and nuclear fuels.
2. What is the use of surge tank in hydroelectric power plant?
A surge tank is provided in a hydroelectric plant to control pressure variations in the penstock. It protects the pipeline from water hammer effects caused by sudden load changes. It also stabilizes the flow of water to the turbine.
3. Define System, Boundary, Surroundings.
- A system is a defined quantity of matter or region selected for study.
- The boundary is the real or imaginary surface separating the system from surroundings.
- Everything outside the boundary is called surroundings.
4. Define closed, open and isolated system.
- A closed system allows energy transfer but not mass transfer across its boundary.
- An open system permits both mass and energy transfer.
- An isolated system allows neither mass nor energy exchange.
5. Difference between intensive and extensive properties
Intensive properties do not depend on the quantity of matter, such as temperature and pressure.
Extensive properties depend on the mass of the system, such as volume and energy. Extensive properties change with system size, while intensive ones remain constant.
6. Difference between diathermic and adiabatic process.
In a diathermic process, heat transfer between system and surroundings is allowed.
In an adiabatic process, no heat transfer occurs across the boundary. Adiabatic processes are usually well insulated.
7. Difference between pump and turbine.
A pump converts mechanical energy into fluid energy to increase pressure.
A turbine converts fluid energy into mechanical work. Pumps require external power, whereas turbines produce power.
8. State Zeroth law of thermodynamics.
The Zeroth law states that if two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other. This law forms the basis for temperature measurement.
9. State First law of thermodynamics.
The First law states that energy cannot be created or destroyed, only transformed. For a closed system, heat added equals the increase in internal energy plus work done. It represents conservation of energy.
10. Second law of thermodynamics – Clausius and Kelvin-Planck statements
Clausius statement says heat cannot flow spontaneously from a colder body to a hotter body.
Kelvin-Planck statement says no heat engine can convert all heat into work in a cycle. Both statements express limitations on energy conversion.
Unit II
1. Define Heat Engine
A heat engine is a device that converts thermal energy into mechanical work. It operates between a high temperature source and a low temperature sink. It works on a thermodynamic cycle.
2. List components of Heat Engine
The main components are a heat source, working substance, heat sink, and mechanical output device. The working substance absorbs heat and produces work. The sink receives the rejected heat.
3. What is TDC and BDC?
TDC (Top Dead Centre) is the highest position of the piston inside the cylinder.
BDC (Bottom Dead Centre) is the lowest position of the piston. These positions define the piston stroke length.
4. What is clearance volume?
Clearance volume is the space remaining in the cylinder when the piston is at TDC. It prevents mechanical contact between piston and cylinder head. It also influences compression ratio.
5. List performance parameters of engine
Common performance parameters include indicated power, brake power, mechanical efficiency, and thermal efficiency. Specific fuel consumption and mean effective pressure are also important. These parameters evaluate engine efficiency and output.
6. Difference between air cooling and water cooling
Air cooling uses air flow to remove engine heat directly from fins.
Water cooling uses circulating coolant to absorb and carry away heat. Water cooling provides better temperature control than air cooling.
7. List properties of lubricant
Lubricants should have suitable viscosity, high flash point, and low pour point. They must resist oxidation and prevent corrosion. Good lubricants reduce friction and wear.
8. Define boiler and classify them
A boiler is a closed vessel in which water is converted into steam by heating. Boilers are classified as fire-tube and water-tube types. They can also be classified based on pressure and circulation method.
9. List boiler mountings and accessories
Boiler mountings include safety valve, pressure gauge, water level indicator, and stop valve.
Boiler Accessories include economizer, superheater, and air preheater. Mountings ensure safety, while accessories improve efficiency.
10. Difference between impulse and reaction turbine
In an impulse turbine, water pressure remains constant across the runner.
In a reaction turbine, pressure changes as water flows through the blades. Impulse turbines use high velocity jets, while reaction turbines use pressure energy.
Unit III
1. What is a centrifugal pump?
A centrifugal pump is a hydraulic machine that increases fluid pressure using centrifugal force. It consists of an impeller rotating inside a casing. It is widely used for water supply and irrigation.
2. What is a Pelton turbine?
A Pelton turbine is an impulse turbine used for high head applications. It uses water jets striking bucket-shaped blades. It converts kinetic energy of water into mechanical energy.
3. Use of braking jet in Pelton turbine
The braking jet is used to stop the runner quickly during shutdown. It directs a jet opposite to the rotation direction. This reduces stopping time and improves safety.
4. Applications of Pelton turbine
- Pelton turbines are used in high head, low discharge hydroelectric plants.
- They are suitable for mountainous regions.
- They are commonly installed in small and medium hydro projects.
5. What is a Kaplan turbine?
A Kaplan turbine is a reaction turbine used for low head and high flow conditions. It has adjustable blades for better efficiency. It operates similar to a propeller.
6. Difference between Kaplan and Francis turbine
- Kaplan turbine is used for low head and high discharge conditions.
- Francis turbine is used for medium head applications.
- Kaplan has adjustable runner blades, while Francis has fixed blades.
7. Define Refrigerant
A refrigerant is a working fluid used in refrigeration systems. It absorbs heat at low temperature and pressure and releases it at high temperature. It undergoes phase change during the cycle.
8. Define One Ton of Refrigeration
One ton of refrigeration is the cooling effect required to freeze one ton of water into ice in 24 hours. It is equal to 3.517 kW of cooling capacity. It represents the rate of heat removal.
Unit IV
ENGINEERING MATERIALS
Classification of Engineering Materials
Engineering materials are classified into metals, ceramics, polymers, and composites based on their physical and mechanical properties. Metals are strong, durable, and good conductors of heat and electricity, while ceramics are hard and resistant to heat and wear. Polymers are lightweight and flexible, whereas composites combine two or more materials to achieve improved properties for engineering applications.
Example: Steel in buildings, plastic in bottles, ceramic tiles, fiberglass in boats.
What are Ferrous and Non-Ferrous Metals?
Ferrous metals contain iron as their main element and are generally strong, hard, and magnetic, but they are prone to rusting when exposed to moisture. Non-ferrous metals do not contain iron and are usually lightweight, corrosion-resistant, and good conductors of electricity and heat. These metals are widely used in industries depending on strength, weight, and corrosion requirements.
Example: Steel used in bridges; aluminium in aircraft.
Mechanical Properties of Materials
Mechanical properties describe the behavior of materials when external forces such as tension, compression, bending, or impact are applied. Important mechanical properties include strength, hardness, toughness, elasticity, ductility, and brittleness. These properties help engineers select suitable materials for machines, tools, and structural components.
Example: Rubber is elastic, glass is brittle.
Properties of Cast Iron
Cast iron is a strong engineering material known for its high compressive strength, good wear resistance, and excellent casting ability. It can absorb vibrations effectively, which makes it useful in heavy machinery and machine foundations. However, cast iron is brittle and can break suddenly under tensile or impact loading.
Example: Used in machine bases.
Applications of Cast Iron
Cast iron is widely used in engineering applications where strength, rigidity, and wear resistance are important. It is commonly used for engine blocks, machine tool structures, pipes, and industrial equipment because it is economical and easy to cast into complex shapes. Its vibration damping property also makes it suitable for heavy machine components.
Example: Lathe machine beds.
Types of Cast Iron
Cast iron is mainly classified into grey cast iron, white cast iron, malleable cast iron, and ductile cast iron based on carbon structure and properties. Grey cast iron has good machinability, white cast iron is hard and wear-resistant, malleable cast iron is tougher, and ductile cast iron has high strength and flexibility. Each type is selected according to industrial requirements.
Example: Ductile iron used in pipes.
Constituents of Cast Iron
The main constituents of cast iron are iron, carbon, silicon, manganese, sulfur, and phosphorus. Carbon improves hardness and casting properties, while silicon enhances machinability and fluidity during casting. Small amounts of sulfur and phosphorus influence brittleness and strength characteristics of the material.
Example: High carbon increases hardness.
Applications of Steel
Steel is one of the most widely used engineering materials because of its high strength, toughness, and versatility. It is extensively used in construction, transportation, manufacturing, and machine tools due to its excellent mechanical properties. Different grades of steel are selected depending on the required strength and durability.
Example: Steel in buildings and railways.
Types of Steels
Steels are commonly classified into low carbon steel, medium carbon steel, and high carbon steel based on carbon content. Low carbon steel is soft and ductile, medium carbon steel provides balanced strength and toughness, while high carbon steel is very hard and wear-resistant. The carbon percentage directly affects the hardness and machinability of steel.
Example: High carbon steel in cutting tools.
Effects of Alloying Elements
Alloying elements are added to steel and other metals to improve properties such as strength, hardness, corrosion resistance, and toughness. Elements like chromium, nickel, molybdenum, and manganese modify the structure of metals and enhance performance under different working conditions. Alloying helps produce materials suitable for specialized industrial applications.
Example: Chromium in stainless steel.
Stainless Steel
Stainless steel is an alloy steel containing chromium, which provides excellent corrosion resistance and durability. It has good strength, attractive appearance, and resistance to rust even in moist environments. Stainless steel is widely used in kitchens, medical equipment, chemical industries, and construction works.
Example: Used in utensils.
Aluminium
Aluminium is a lightweight metal with good corrosion resistance, high thermal conductivity, and excellent machinability. It is widely used where low weight and high strength-to-weight ratio are required. Aluminium can also be recycled easily, making it an environmentally friendly engineering material.
Example: Aircraft bodies.
Copper
Copper is a soft and ductile metal known for its excellent electrical and thermal conductivity. It is widely used in electrical systems, electronics, and heat transfer equipment because it efficiently carries electricity and heat. Copper also has good corrosion resistance and long service life.
Example: Electrical wiring.
Composite Material
Composite materials are formed by combining two or more different materials to obtain improved mechanical and physical properties. These materials provide high strength, low weight, and better durability compared to individual materials used alone. Composites are widely used in aerospace, automotive, and construction industries.
Example: Reinforced concrete.
Ceramics
Ceramics are non-metallic materials that are hard, brittle, and highly resistant to heat and corrosion. They can withstand high temperatures and are often used in electrical insulation and refractory applications. Although ceramics are strong in compression, they are weak under tensile and impact loads.
Example: Tiles and insulators.
Unit V
TRANSMISSION OF MOTION AND POWER
What is shaft, spindle and axle?
A shaft is a rotating machine element used to transmit power and motion from one part of a machine to another. A spindle is a short rotating shaft mainly used to support and rotate cutting tools or workpieces in machine tools. An axle supports rotating parts such as wheels and gears but usually does not transmit power.
What are the elements of power transmission?
The main elements of power transmission are shafts, belts, chains, gears, pulleys, and couplings. These components help transfer mechanical power and motion from a driving machine to a driven machine. They are widely used in automobiles, industrial machinery, and manufacturing equipment.
What is belt drive?
A belt drive is a mechanical system used to transmit power between rotating shafts using belts and pulleys. It provides smooth and quiet operation and is suitable for transmitting power over long distances. Belt drives are commonly used in fans, conveyors, and machine tools.
List the types of belt drives
The common types of belt drives are open belt drive, crossed belt drive, and compound belt drive. Open belt drives rotate pulleys in the same direction, while crossed belt drives rotate them in opposite directions. Compound belt drives are used when large speed reduction or transmission over long distances is required.
List the types of belts
The main types of belts used in power transmission are flat belts, V-belts, and circular belts. Flat belts are suitable for high-speed applications, while V-belts provide better grip and reduced slipping. Circular belts are mainly used for light-duty applications.
List the materials used for belts
Belts are manufactured using materials such as leather, rubber, cotton, and synthetic materials. Leather belts are strong and flexible, while rubber belts provide good friction and durability. Synthetic belts are widely used because of their high strength and resistance to wear.
What is chain drive?
A chain drive is a power transmission system that uses a chain and sprockets to transfer motion and power between shafts. Unlike belt drives, chain drives provide positive transmission without slipping. They are commonly used in bicycles, motorcycles, and conveyor systems.
List the types of chain drive
The main types of chain drives are hoisting chains, conveyor chains, and power transmission chains. Hoisting chains are used for lifting loads, conveyor chains are used in material handling systems, and power transmission chains are used in machinery and vehicles. Each type is designed for specific industrial applications.
What is pulley and types
A pulley is a wheel with a grooved rim used along with belts or ropes to transmit power or lift loads. The main types of pulleys are fixed pulleys, movable pulleys, and compound pulleys. Pulleys help reduce effort and change the direction of force in mechanical systems.
What is gear train and types
A gear train is a combination of two or more gears used to transmit motion and change speed or torque between shafts. The main types are simple gear train, compound gear train, reverted gear train, and epicyclic gear train. Gear trains are widely used in automobiles, clocks, and industrial machines.
What is the purpose of clutches and types
A clutch is a mechanical device used to connect or disconnect power transmission between the engine and the driven shaft. It allows smooth starting and stopping of machines and vehicles without shutting down the engine. Common types of clutches are single plate clutch and multi-plate clutch.
What is the purpose of brake and types
A brake is a device used to slow down or stop the motion of a moving machine or vehicle by converting kinetic energy into heat. Brakes ensure safety and control in automobiles and industrial equipment. The common types of brakes are disc brakes and drum brakes.
Unit VI
ROBOTICS AND CNC
Define robot and list components
A robot is a programmable automated machine capable of performing tasks with speed, accuracy, and efficiency.
The main components of a robot are manipulator, controller, sensors, power supply, and end effectors. Robots are widely used in industries for welding, painting, assembly, and material handling operations.
What is manipulator?
A manipulator is the mechanical arm of a robot that performs movement and handling operations. It consists of links and joints that provide flexibility and motion similar to a human arm. Manipulators are used for tasks such as welding, pick-and-place operations, and machine loading.
What are the Applications of robots
Robots are widely used in manufacturing industries for welding, painting, assembly, and packaging operations. They are also used in medical fields for surgeries and in hazardous environments where human safety is at risk. Robotics improves productivity, precision, and workplace safety.
What are the types of sensors used in robots
Robots use different types of sensors such as position sensors, proximity sensors, vision sensors, and force sensors. These sensors help robots detect movement, distance, objects, and applied force for accurate operation. Sensors play an important role in robot automation and intelligent control.
List the components of CNC machine
The main components of a CNC machine are input device, machine control unit, machine tool, drive system, and feedback system.
The input device provides machining instructions, while the control unit processes commands and controls operations.
The feedback system ensures accuracy by continuously monitoring machine performance.
What is machining center?
A machining center is an advanced CNC machine capable of performing multiple machining operations such as drilling, milling, boring, and tapping automatically.
It increases productivity and accuracy by reducing manual intervention and setup time. Machining centers are widely used in modern manufacturing industries.
What is adaptive control?
Adaptive control is a system in CNC machining that automatically adjusts machining parameters such as speed, feed, and cutting conditions during operation. It improves machining efficiency, tool life, and product quality. Adaptive control helps machines respond effectively to changing working conditions.
Difference between NC, CNC, and DNC
NC (Numerical Control) machines use punched tapes or manual instructions for controlling machining operations.
CNC (Computer Numerical Control) machines use computers for automatic and flexible machine control with higher accuracy.
DNC (Direct Numerical Control) systems connect multiple CNC machines to a central computer for centralized monitoring and program management.