Karnataka SSLC Automobile - NSQF (KSEAB) cheat sheet

Personal protective equipment (PPE) for workshop use: safety goggles, steel-toe boots, coveralls, and gloves; ear protection above 85 dB(A) and a welding helmet with shade 10-13 for arc welding.

Fire classes and correct extinguishers: Class A (solids) water/foam; Class B (petrol, diesel, solvents) foam, dry powder, CO2; Class C (flammable gas) dry powder; electrical fires CO2 or dry powder, never water.

Compressed air must never be used to clean skin or clothing; workshop air lines are regulated to about 6-8 bar and can inject air through skin cuts.

Jack and axle-stand rule: a hydraulic jack lifts only; axle stands or ramps must support the vehicle before any part of the body goes underneath.

Petrol flash point is about -43 degrees C, so no smoking, open flame, or mobile phones within 3 m of fuel handling; fuel is drained into approved metal containers only.

Battery charging releases hydrogen; keep vents open, connect positive last and disconnect negative first, and never charge a frozen battery.

Carbon monoxide from running engines is odourless; engines are run only with the exhaust hose attached, never in a closed bay.

Eye-wash fountains and first-aid boxes are placed within 10 seconds' walk of battery, fuel, and grinding stations; spill kits for oil use absorbent granules, not water washing into drains.

Lockout/tagout applies before working on fans, belts, or lift hydraulics: isolate the power source, tag it, and confirm zero energy before contact.

Micrometer least count = pitch of screw thread divided by number of divisions on the thimble; a 0.5 mm pitch with a 50-division thimble gives 0.01 mm.

Vernier calliper least count = 1 main-scale division (usually 1 mm) divided by number of vernier divisions; 50 vernier divisions give 0.02 mm.

Torque wrench reading is valid only over the middle 20-80 percent of its scale; recheck calibration at least annually and return the setting to zero after use.

Spanner size refers to the across-flats distance of the nut; a 13 mm spanner fits a nut with 13 mm across flats, not the thread diameter.

Feeler gauges measure gaps such as valve clearance and spark plug gap; combine blades to build the required thickness and never force a blade.

A dial test indicator (DTI) with 0.01 mm resolution is used for runout, end play, and shaft deflection; magnetic base must be clamped to a clean, rigid surface.

Special service tools: valve spring compressor for valve removal, piston ring expander for ring fitting, bearing puller for press-fit bearings, and a ball-joint separator for taper joints.

A bench grinder is dressed with a wheel dresser to keep the face flat; the tool rest is set within 2 mm of the wheel and the spark guard within 3 mm.

Hydraulic press capacity must exceed the required extraction force; never stand in line with the ram during pressing to avoid injury from sudden release.

Four-stroke cycle order: intake, compression, power, exhaust; the crankshaft makes two revolutions per complete cycle and the camshaft makes one.

Compression ratio = (swept volume + clearance volume) divided by clearance volume; petrol engines commonly run 8:1 to 12:1, diesel 16:1 to 22:1.

Engine displacement = cylinder area x stroke x number of cylinders; a 4-cylinder engine with 80 mm bore and 90 mm stroke displaces about 1809 cc.

Valve clearance is measured cold for most engines with a feeler gauge; too little clearance causes valve leakage and burnt valves, too much causes noise and reduced lift.

Firing order determines ignition and injection sequencing; common orders are 1-3-4-2 (inline four) and 1-5-3-6-2-4 (inline six).

Diesel compression-ignition needs fuel injection pressure of several hundred bar (common rail up to about 2000 bar); petrol port injection runs at 3-4 bar.

Timing belt alignment marks must line up with the camshaft and crankshaft marks; on interference engines a misaligned belt bends valves on first start.

Turbocharger boost is limited by a wastegate or variable nozzle; a stuck wastegate causes overboost and detonation, a leaking intake causes low boost and black smoke on diesel.

Oil pressure warning at idle with correct oil level points to a worn oil pump or excessive bearing clearance; verify with a mechanical gauge before condemning parts.

Manual gearbox gear ratio = teeth on driven gear divided by teeth on driving gear; overall ratio is the product of gearbox ratio and final drive ratio.

Clutch transmits torque through friction between flywheel, friction disc, and pressure plate; free play at the pedal is typically 10-25 mm and must be adjusted to prevent slip or drag.

A clutch that slips under load shows rising engine speed without vehicle speed increase; a clutch that drags causes gear engagement noise and creep.

Torque converter in an automatic multiplies torque at low speed through the stator; stall speed is the maximum engine speed with the output held stationary.

Automatic transmission fluid (ATF) level is checked with the engine running at operating temperature in Park or Neutral as specified, never with the engine off.

Constant velocity (CV) joints on front-wheel drive use a bellows boot; a torn boot loses grease and causes clicking on turns.

Differential gear ratio = ring gear teeth divided by pinion teeth; a limited-slip differential uses clutch packs or a viscous coupling to limit wheel spin.

Final drive hypoid gears require special hypoid gear oil (API GL-5) because of high sliding pressure at the tooth contact.

Steering ratio = steering wheel rotation divided by road wheel rotation; a higher ratio reduces effort but slows response.

Ackermann geometry makes the inner wheel turn more than the outer wheel so both wheels follow concentric circles without tyre scrub.

Caster, camber, toe, and kingpin inclination (KPI) form wheel alignment; toe-in is measured in mm or degrees and incorrect toe causes rapid, feathered tyre wear.

Positive camber tilts the top of the wheel outward; excessive negative camber wears the inner tyre edge.

Suspension types: MacPherson strut (integrated spring and damper), double wishbone, torsion bar, and leaf spring for load carrying; dampers convert motion to heat.

Brake pedal free play is typically 5-20 mm; excessive free play means air in the hydraulic system or a worn master cylinder pushrod setting.

Hydraulic brake force multiplication follows Pascal's law: pressure is equal throughout the fluid, so a larger wheel cylinder piston gives greater clamping force.

Brake fluid is hygroscopic; DOT 4 absorbs moisture and is replaced every 2 years or when moisture exceeds about 3 percent by tester.

Drum brake self-energising effect: leading shoe is dragged into contact by drum rotation, giving higher braking force in forward direction than in reverse.

ABS prevents wheel lock by modulating pressure at 10-20 cycles per second; a lit ABS warning means the system is disabled but base braking remains.

Ohm's law: V = I x R; power P = V x I = I squared x R. A 55 W headlamp on 12 V draws about 4.6 A.

Lead-acid cell gives about 2.1 V; a 12 V battery has six cells in series and is fully charged at about 12.6-12.8 V rest, 13.8-14.4 V while charging.

Battery capacity is rated in ampere-hours (Ah) at the 20-hour rate; cold cranking amps (CCA) indicate starting ability at low temperature.

Starter motor draws 100-300 A; a voltage drop above 0.5 V on the earth or positive cable causes slow cranking.

Alternator output is regulated to about 14.2 V; a faulty rectifier causes ripple and dim, flickering lights.

Series circuit: current is the same everywhere, voltages add. Parallel circuit: voltage is the same, currents add.

Fuses are rated to protect wiring; replacing a blown fuse with a higher rating overheats the circuit and risks fire.

CAN bus is a two-wire differential network (CAN-H and CAN-L) at 500 kbps in most vehicles; a shorted bus line disables multiple modules.

LED and HID lamps need correct polarity and ballast; HID lamps strike at several hundred volts and must not be handled with bare hands.

Petrol stoichiometric air-fuel ratio is about 14.7:1 by mass; diesel is about 14.5:1. Rich mixture means excess fuel, lean means excess air.

Fuel pump pressure: port injection 3-4 bar, direct injection 50-200 bar, common-rail diesel up to about 2000 bar; a blocked filter shows low pressure and lean codes.

SAE oil viscosity grade: the first number with W is cold-flow rating, the second is hot viscosity; 15W-40 flows like 15 grade cold and 40 grade hot.

API service categories: S for spark ignition (petrol), C for compression ignition (diesel); a higher letter is a later, more demanding specification.

Oil pump is usually gear or rotor type driven from the crankshaft; a pressure relief valve limits maximum pressure and opens when oil is cold.

Cooling system: thermostat opens at about 82-90 degrees C, coolant boils at 100 degrees C at sea level but at about 120 degrees C with a 1 bar cap and 50 percent glycol.

Coolant is a 50:50 mix of ethylene glycol and water for freeze protection to about -37 degrees C and boil protection; never open a hot pressurised cap.

Radiator cap rating 0.9-1.1 bar raises boiling point and must match the specification; a weak cap causes overheating at high load.

Air filter restriction raises intake vacuum and enriches carburetted mixtures; a clogged filter reduces power and increases fuel consumption.

Periodic service intervals are set by distance or time, whichever comes first; typical first service is at 1000 km or 1 month for oil and fastener checks.

Daily checks: engine oil level on level ground with engine off, coolant level cold, brake fluid level, tyre pressure cold, and lamp function.

Tyre pressure is checked cold; pressure rises about 0.3 bar when hot, so never bleed a hot tyre to the cold specification.

Tread depth minimum is 1.6 mm; wear indicator bars sit at 1.6 mm across the tread grooves.

Tyre rotation pattern depends on drive type; radial tyres keep the same rotation direction, so front-to-rear on the same side is used.

Pre-delivery inspection (PDI) covers fluid levels, battery charge, tyre pressure, wheel nut torque, lamp and horn function, and road test.

Emission inspection: CO and HC limits apply to petrol engines at idle and fast idle; excessive CO indicates a rich mixture or faulty oxygen sensor.

Brake inspection measures pad or lining thickness against the wear limit, disc runout with a DTI, and drum ovality; brake fluid moisture is checked with a tester.

Service record must list parts replaced, fluid grades and quantities, torque values applied, and the next due date or distance.

Panel damage classification: minor dent (paint intact) uses paintless dent removal; creased panel needs panel beating, filler, and refinish; structural damage needs a jig and measuring system.

Sheet metal gauge: lower gauge number means thicker metal; body panels commonly use 0.7-1.0 mm mild steel or aluminium alloy.

Body filler is applied over bare, abraded metal in thin coats; a filler layer thicker than about 3 mm is prone to cracking and should be replaced by metal work.

Sandpaper grit sequence for refinish: 80-120 for stripping, 180-240 for filler shaping, 400-600 for primer, 800-1500 for blending and clear coat preparation.

Primer types: etch primer for bare aluminium and steel, epoxy primer for corrosion protection, and primer surfacer for filling and sanding.

Paint mixture ratio must follow the product data sheet; base coat plus thinner plus hardener in the stated ratio, with pot life typically 4-8 hours.

Spray gun settings: fluid needle, air cap pattern, and pressure (commonly 2-3 bar at the cap for HVLP); distance to panel about 15-20 cm with 50 percent overlap.

Orange peel indicates too little thinner, low pressure, or too fast a pass; runs indicate too much material or too slow a pass.

Polishing removes oxidation and fine scratches with a compound and foam pad; detailing includes clay bar decontamination, glaze, sealant, and interior cleaning.

Communication process: sender, message, channel, receiver, feedback; feedback confirms the message was understood.

Active listening: maintain eye contact, do not interrupt, paraphrase the message back, and ask clarifying questions.

Resume structure: personal details, career objective, education, technical skills, project or practical experience, and references.

Job interview protocol: research the employer, arrive 10-15 minutes early, greet with a firm handshake, answer in specific examples, and follow up with a thank-you note.

Teamwork roles: leader, facilitator, contributor, and recorder; conflict is resolved by focusing on the problem, not the person.

Workplace ethics: punctuality, honesty in reporting work done, confidentiality of customer data, and respect for safety rules.

Time management: prioritise tasks by urgency and importance, plan the day in the first 10 minutes, and record completed work.

Digital skills: email etiquette (clear subject, concise body, attachment named), spreadsheet basics for parts inventory, and safe password practice.

Right to safety, right to information, and right to be heard are consumer rights relevant to service work and warranty claims.

Break-even quantity = fixed cost divided by (selling price per unit minus variable cost per unit).

Gross profit = revenue minus cost of goods sold; net profit = gross profit minus operating expenses.

Working capital = current assets minus current liabilities; a workshop needs cash for parts, wages, and rent before customer payment arrives.

GST registration threshold for a small service business and correct tax invoice fields: GSTIN, invoice number, date, description, HSN or SAC code, taxable value, tax rate, and total.

Job card is the legal record of customer complaint, work authorised, parts used, labour hours, and signature on delivery.

Estimate versus invoice: the estimate is given before work and the invoice after; any extra work needs fresh customer approval.

Inventory control: minimum stock level, reorder level, and economic order quantity reduce blocked capital and stock-outs.

Labour charge is calculated as standard time x hourly rate; overhead recovery adds rent, power, and tool depreciation to the hourly rate.

Business plan sections: market and customers, services offered, location, equipment and investment, manpower, cost structure, and projected profit.

Practical assessment is scored on safety compliance, correct tool selection, procedure sequence, measurement accuracy, finish quality, and time taken.

Before starting any practical task, state the job sequence aloud and confirm PPE; an unsafe start is a fail regardless of the finished result.

Measurement reporting uses the correct unit and resolution: vernier 0.02 mm, micrometer 0.01 mm, torque in Nm, pressure in bar or kPa.

Torque sequence for a cylinder head is from centre outward in stages, following the manufacturer's pattern; a single pass causes head distortion.

Project report structure: title, objective, tools and materials, procedure, observations with readings, result, conclusion, and safety precautions.

Troubleshooting follows a logical path: confirm the complaint, gather symptoms, form a hypothesis, test with instruments, repair, and verify by road test.

Record readings in a table with units and repeat each critical measurement three times; report the average and note deviations.

Work area discipline (5S): sort, set in order, shine, standardise, sustain; tools are returned to marked positions after every job.

Verification after repair includes fluid level check, leak check, function test, and a short road test with the customer complaint re-checked.