I85PREP
⌘ K
UPMSP High School Automobile study materials
UPMSP High School Automobile study resources

UPMSP High School Automobile practice questions

One question at a time. Build your UPMSP High School Automobile understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Automobile Basics and Workshop Safety

In an automobile workshop, which personal protective equipment is most important when grinding metal parts on a bench grinder?

  1. Ordinary spectacles
  2. Cotton gloves and a loose apron
  3. Safety goggles and a face shield Correct answer.
  4. A dust mask only

Explanation

Grinding throws high-speed metal chips and sparks toward the face and eyes, so impact-rated eye protection plus a face shield is the primary safeguard. Loose clothing and ordinary spectacles do not stop flying particles.

Question 2Automobile Basics and Workshop Safety

A four-stroke petrol engine completes one full working cycle in how many revolutions of the crankshaft?

  1. Four
  2. Two Correct answer.
  3. One
  4. Half

Explanation

The four strokes are intake, compression, power and exhaust, and each stroke takes half a crankshaft revolution. Therefore one complete cycle takes two revolutions of the crankshaft.

Question 3Automobile Basics and Workshop Safety

Which component in a manual transmission allows the driver to engage gears smoothly by matching the speed of the engine and the gearbox input shaft?

  1. Torque converter
  2. Radiator
  3. Differential
  4. Clutch Correct answer.

Explanation

The clutch temporarily disconnects and progressively reconnects the engine from the gearbox, allowing shaft speeds to synchronise during gear changes. The differential and radiator perform unrelated functions, and a torque converter is used in automatic transmissions.

Question 4Automobile Basics and Workshop Safety

What is the main purpose of the radiator in a liquid-cooled engine cooling system?

  1. To store fuel for the engine
  2. To increase engine oil pressure
  3. To filter dust from the intake air
  4. To release heat from the coolant to the surrounding air Correct answer.

Explanation

Hot coolant flows through the radiator tubes and transfers heat to the air passing over the fins. This keeps the engine within its correct operating temperature range.

Question 5Automobile Basics and Workshop Safety

Before working underneath a vehicle raised on a hydraulic trolley jack, what is the correct safety practice?

  1. Ask a helper to hold the vehicle steady
  2. Place axle stands under the chassis at the specified jacking points Correct answer.
  3. Lower the vehicle onto the wheels first
  4. Leave the jack holding the load alone

Explanation

A hydraulic jack can lose pressure suddenly, so it is only a lifting device. Rigid axle stands placed at manufacturer-specified points must support the vehicle before any part of the body goes underneath.

Question 6Automobile Basics and Workshop Safety

Which tool is designed to measure the diameter of a cylinder bore with high accuracy?

  1. Feeler gauge
  2. Torque wrench
  3. Vernier caliper
  4. Inside micrometer Correct answer.

Explanation

An inside micrometer has measuring anvils arranged to contact the internal walls of a bore and reads directly in fine increments. A vernier caliper can measure inside diameters but with less precision for engine work.

Question 7Automobile Basics and Workshop Safety

In a lead-acid automotive battery, what does each cell produce nominally?

  1. 1.2 volts
  2. 6 volts
  3. 2.1 volts Correct answer.
  4. 12 volts

Explanation

Each lead-acid cell produces about 2.1 volts when fully charged, so six cells in series give the familiar nominal 12-volt battery. The cell voltage comes from the lead and lead dioxide electrodes in sulphuric acid.

Question 8Automobile Basics and Workshop Safety

Which fire extinguisher class is appropriate for a burning petrol spill in the workshop?

  1. Class B foam or dry powder Correct answer.
  2. Class D metal powder
  3. Class A water
  4. Class C only

Explanation

Petrol is a flammable liquid, which places it in Class B. Foam and dry powder smother the surface and cut off oxygen, while water spreads the burning liquid.

Question 9Automobile Basics and Workshop Safety

During the compression stroke of a diesel engine, what is compressed?

  1. Air and fuel mixture
  2. Exhaust gas
  3. Fuel only
  4. Air only Correct answer.

Explanation

In a diesel engine only air is drawn in and compressed to a high ratio, raising its temperature above the fuel's ignition point. Fuel is injected near the end of compression and ignites spontaneously.

Question 10Automobile Basics and Workshop Safety

A vehicle pulls to one side while braking. Which fault is the most likely cause?

  1. Low coolant level
  2. Incorrect tyre rotation direction only
  3. A worn windscreen wiper
  4. Unequal braking force at the front wheels Correct answer.

Explanation

If one front brake applies more force than the other, the vehicle yaws toward the stronger side during braking. Common causes include a seized caliper, a blocked brake line or contaminated linings on one side.

Question 11Automobile Basics and Workshop Safety

What is the function of the synchroniser rings in a manual gearbox?

  1. To cool the gearbox oil
  2. To lock the output shaft permanently
  3. To increase engine torque
  4. To equalise the speed of the gear and the shaft before engagement Correct answer.

Explanation

Synchroniser rings use friction to bring the gear and shaft to the same speed before the dog teeth engage. This prevents clashing and allows smooth gear selection.

Question 12Automobile Basics and Workshop Safety

When jump-starting a vehicle with a flat battery from a donor battery, which connection is made last?

  1. Positive terminal of the flat battery
  2. Negative terminal of the flat battery to a clean engine earth Correct answer.
  3. Positive terminal of the donor battery
  4. Negative terminal of the donor battery

Explanation

The final connection is the negative lead to a clean earth point on the disabled vehicle, away from the battery. This keeps any spark away from hydrogen gas venting from the battery.

Question 13Automobile Basics and Workshop Safety

Which wheel alignment angle describes the tilt of the steering axis from vertical when viewed from the front of the vehicle?

  1. Camber Correct answer.
  2. Toe-in
  3. Caster
  4. Thrust angle

Explanation

Camber is the inward or outward tilt of the wheel and steering axis measured from vertical in the front view. Caster is measured in the side view, and toe is measured in the plan view.

Question 14Automobile Basics and Workshop Safety

What does a flashing oil pressure warning lamp on the instrument panel most likely indicate?

  1. The oil level is too high
  2. The engine coolant is boiling
  3. Oil pressure is dangerously low Correct answer.
  4. The oil filter is new

Explanation

The oil pressure switch closes when pressure falls below a safe value, illuminating the lamp. Continued running with low pressure can destroy bearings, so the engine should be stopped and the cause checked.

Question 15Automobile Basics and Workshop Safety

Which type of tyre construction uses body cords running radially from bead to bead at about 90 degrees to the centreline?

  1. Bias-belted
  2. Cross-ply
  3. Solid rubber
  4. Radial-ply Correct answer.

Explanation

In a radial-ply tyre the cords run straight across the casing at roughly right angles to the tread centreline, with a belt package underneath the tread. This gives better tread stability and lower rolling resistance than cross-ply construction.

Question 16Automobile Basics and Workshop Safety

A technician finds that the engine cranks slowly and the battery terminals are clean but warm after cranking. What is the most reasonable next check?

  1. Replace the spark plugs
  2. Check the battery state of charge and the earth strap resistance Correct answer.
  3. Top up the windscreen washer
  4. Adjust the valve clearance

Explanation

Slow cranking with warm terminals points to high resistance or a weak battery, so the battery's state of charge and the earth strap should be tested. Warm terminals suggest current is being lost as heat at a poor connection.

Question 17Automobile Basics and Workshop Safety

Why is a torque wrench preferred over a standard spanner when tightening cylinder head bolts?

  1. It tightens faster
  2. It applies a measured clamping force in the correct sequence Correct answer.
  3. It removes damaged threads
  4. It avoids the need for a gasket

Explanation

Cylinder head bolts must be tightened to a specified torque in a defined sequence to distribute clamping load evenly and avoid warping. A torque wrench gives a measurable, repeatable force.

Question 18Automobile Basics and Workshop Safety

What is the main advantage of fuel injection over a carburettor in a modern petrol engine?

  1. It needs no fuel pump
  2. It eliminates the need for a throttle
  3. It removes the need for an exhaust system
  4. It delivers a more precisely metered air-fuel mixture to each cylinder Correct answer.

Explanation

An electronic fuel injection system meters fuel according to measured air mass and engine conditions, giving better economy and lower emissions. A carburettor relies on airflow and venturi effects, which are less precise.

Question 19Automobile Basics and Workshop Safety

In a hydraulic braking system, what does the master cylinder do when the brake pedal is pressed?

  1. Measures wheel speed
  2. Converts pedal force into hydraulic pressure in the brake lines Correct answer.
  3. Stores hydraulic fluid for the calipers
  4. Cools the brake discs

Explanation

The master cylinder piston pressurises brake fluid, which transmits force through the lines to the wheel cylinders or calipers. This hydraulic pressure then applies the friction linings to the discs or drums.

Question 20Automobile Basics and Workshop Safety

A vehicle has excessive play in the steering wheel. Which component should be inspected first?

  1. The air filter housing
  2. The steering rack or steering box mountings and tie-rod ends Correct answer.
  3. The radiator cap
  4. The fuel filler cap

Explanation

Excessive free play usually comes from wear in the steering box, rack mountings or tie-rod ends. These joints transfer steering input to the wheels, so wear there produces lost motion.

Question 21Automobile Basics and Workshop Safety

A four-cylinder four-stroke engine has a firing order of 1-3-4-2. If cylinder 1 fires at 0 degrees of crankshaft rotation, at what angle does cylinder 4 fire?

  1. 720 degrees
  2. 180 degrees
  3. 360 degrees
  4. 540 degrees Correct answer.

Explanation

In a four-cylinder four-stroke engine the firing intervals are 180 degrees because 720 degrees is divided among four cylinders. Counting 1 at 0, 3 at 180 and 4 at 360 would be wrong for this order, so the sequence 1-3-4-2 places cylinder 4 at 360 plus 180, that is 540 degrees.

Question 22Automobile Basics and Workshop Safety

A petrol engine has low compression on one cylinder that improves slightly when a little oil is added to the bore. What does this indicate?

  1. A leaking intake valve only
  2. Worn piston rings or bore Correct answer.
  3. A faulty spark plug
  4. A blocked exhaust pipe

Explanation

Oil temporarily seals the gap between rings and bore, so compression rises if the rings or bore are worn. A leaking valve would not improve with added oil because the leak path is in the head.

Question 23Automobile Basics and Workshop Safety

Why is a catalytic converter fitted close to the exhaust manifold in many vehicles?

  1. To reach operating temperature quickly for efficient conversion Correct answer.
  2. To reduce exhaust noise
  3. To cool the exhaust gas
  4. To increase engine oil pressure

Explanation

A catalyst only converts gases efficiently above its light-off temperature, so mounting it near the manifold exposes it to hotter gas sooner. This reduces cold-start emissions.

Question 24Automobile Basics and Workshop Safety

A technician measures a cylinder bore and finds it is tapered from top to bottom. What is the most appropriate repair?

  1. Rebore or hone the cylinder to the next oversize and fit matching pistons Correct answer.
  2. Fit new piston rings without machining
  3. Adjust the tappet clearance
  4. Replace the spark plugs

Explanation

Taper means the bore diameter changes along its length, so new rings alone cannot restore a true sealing surface. The correct repair is to machine the bore to a uniform oversize and fit pistons and rings of that size.

Question 25Automobile Basics and Workshop Safety

During a road test, a vehicle's engine speed rises but road speed does not increase proportionally. Which fault is most consistent with this symptom?

  1. A slipping clutch Correct answer.
  2. A faulty horn
  3. A weak battery
  4. A blocked fuel filter

Explanation

If engine speed rises without a matching rise in road speed, the drive is being lost between engine and gearbox. A worn or contaminated clutch friction plate is the classic cause of this slip.

Question 26Automobile Basics and Workshop Safety

A workshop stores petrol in a safety container and notices a small spill on the concrete floor. Which action follows correct workshop safety practice before any repair work continues?

  1. Remove all ignition sources, ventilate the area and clean up with an approved absorbent Correct answer.
  2. Cover the spill with sawdust and continue working nearby
  3. Wash the spill into the floor drain with a bucket of water
  4. Wipe the spill with a dry cotton cloth and store the cloth in a toolbox

Explanation

Petrol vapour is heavier than air, spreads along the floor and ignites easily, so the first priorities are eliminating ignition sources, ventilating the space and absorbing the liquid with a suitable material. Sweeping or washing the spill only spreads the flammable liquid and vapour. Continuing work near an uncovered spill keeps an ignition risk close to the job.

Question 27Automobile Basics and Workshop Safety

A technician must raise a car to work underneath it. Which practice gives a safe and stable support?

  1. Support the sump on a wooden block and keep the jack raised
  2. Leave the hydraulic trolley jack holding the load while working
  3. Rest the chassis on stacked bricks at the jacking points
  4. Place axle stands under the recommended jacking points and lower the jack Correct answer.

Explanation

A hydraulic jack is a lifting device, not a support, because it can lose pressure and drop the vehicle. The vehicle must be transferred onto rated axle stands placed at the manufacturer's jacking points on a level, hard surface. Bricks, wooden blocks and the sump cannot carry the load safely.

Question 28Automobile Basics and Workshop Safety

A mechanic uses a metric micrometer to measure a worn piston skirt. The sleeve shows 42 mm, the thimble reads 28 divisions and the vernier line on the sleeve aligns with the 3rd thimble mark. What is the reading?

  1. 42.308 mm
  2. 42.283 mm Correct answer.
  3. 42.280 mm
  4. 42.530 mm

Explanation

On a metric micrometer with 0.01 mm thimble divisions, the sleeve gives whole and half millimetres, the thimble gives hundredths, and the sleeve vernier line adds thousandths. Here the reading is 42 mm plus 28 × 0.01 mm plus 3 × 0.001 mm, giving 42.283 mm. Each element must be added in the correct place value.

Question 29Automobile Basics and Workshop Safety

Why is a ring spanner generally preferred over an open-ended spanner for breaking loose a tight nut on a suspension component?

  1. It can be extended with a length of pipe for extra leverage
  2. It is lighter, so it transmits more torque to the fastener
  3. It grips all the flats of the nut and resists slipping or rounding Correct answer.
  4. It allows the handle to be angled to reach awkward positions

Explanation

A ring spanner encloses the nut and contacts all six flats, spreading the load and reducing the chance of slipping or rounding the corners. An open-ended spanner contacts only two flats, so it is more likely to slip under high torque. Extending a spanner with a pipe is unsafe practice and not a design advantage.

Question 30Automobile Basics and Workshop Safety

A four-stroke engine is being timed and the technician must identify valve overlap. Which statement correctly describes this condition?

  1. The exhaust valve opens before bottom dead centre and closes after top dead centre only
  2. The inlet and exhaust valves are both open briefly around top dead centre between exhaust and induction Correct answer.
  3. Both valves are closed at the end of the compression stroke to seal the cylinder
  4. The inlet valve closes after bottom dead centre while the exhaust valve remains shut

Explanation

Valve overlap is the short period near top dead centre at the end of the exhaust stroke and start of the induction stroke when both valves are open. The outgoing exhaust gas helps draw in the fresh charge, improving cylinder filling. Overlap is set by the camshaft profile and timing.

Question 31Engine Systems and Components

In a four-stroke petrol engine, which stroke immediately follows the power stroke?

  1. Suction stroke
  2. Injection stroke
  3. Exhaust stroke Correct answer.
  4. Compression stroke

Explanation

The four strokes occur in the fixed order suction, compression, power and exhaust, and the cycle then repeats. After the burning gases have pushed the piston down on the power stroke, the exhaust valve opens and the piston rises to push the burnt gases out.

Question 32Engine Systems and Components

The function of the flywheel in a single-cylinder four-stroke engine is mainly to:

  1. Increase the compression ratio of the engine
  2. Filter the lubricating oil before it reaches the bearings
  3. Open and close the valves at the correct time
  4. Store energy and smooth out the speed fluctuations between power strokes Correct answer.

Explanation

The flywheel is a heavy rotating mass that absorbs energy during the power stroke and releases it during the other three strokes. This keeps the crankshaft turning at a nearly uniform speed despite the intermittent power delivery of a single-cylinder engine.

Question 33Engine Systems and Components

In a compression-ignition (diesel) engine, ignition of the fuel charge occurs because:

  1. The air is compressed to a high temperature and the injected fuel self-ignites Correct answer.
  2. Glow plugs ignite the mixture throughout normal running
  3. The fuel is pre-mixed with air in the carburettor and then burned
  4. A spark plug fires at the end of the compression stroke

Explanation

A diesel engine draws in only air and compresses it to a high pressure, which raises its temperature well above the fuel's ignition point. Fuel injected at the end of compression therefore ignites spontaneously without any external spark.

Question 34Engine Systems and Components

The main purpose of the cooling system in an automobile engine is to:

  1. Lubricate the moving parts of the engine
  2. Increase the power output of the engine
  3. Increase the compression pressure inside the cylinder
  4. Remove excess heat so that the engine runs at its designed operating temperature Correct answer.

Explanation

Combustion produces far more heat than the engine can use, and if this heat is not carried away the metal parts distort and the oil film breaks down. The cooling system keeps the engine within its designed temperature range for efficient and reliable running.

Question 35Engine Systems and Components

Which component converts the reciprocating motion of the piston into rotary motion of the crankshaft?

  1. Push rod
  2. Rocker arm
  3. Camshaft
  4. Connecting rod Correct answer.

Explanation

The connecting rod joins the piston to the crankpin, so as the piston moves up and down the rod swings and turns the crankshaft. This linkage is what changes straight-line piston motion into rotation.

Question 36Engine Systems and Components

In a battery ignition system, the component that steps up the low battery voltage to the high voltage needed at the spark plug is the:

  1. Ignition coil Correct answer.
  2. Condenser
  3. Ballast resistor
  4. Distributor

Explanation

The ignition coil contains primary and secondary windings, and the collapsing magnetic field induces a very high voltage in the many-turn secondary winding. This high voltage is what jumps the spark plug gap.

Question 37Engine Systems and Components

The clearance between the piston and the cylinder wall is measured with a:

  1. Torque wrench
  2. Vernier caliper and micrometer Correct answer.
  3. Feeler gauge only
  4. Dial bore gauge only

Explanation

Piston diameter is measured with an outside micrometer and the cylinder bore with a vernier caliper or bore gauge. The difference between the two readings gives the piston-to-cylinder clearance.

Question 38Engine Systems and Components

The valve clearance in an engine is provided so that:

  1. Oil can drain from the cylinder head
  2. The valve can close fully on its seat despite thermal expansion of the valve train Correct answer.
  3. The valve spring can be made softer
  4. The camshaft can rotate more freely

Explanation

Valve-train parts expand when the engine warms up, so a small clearance is left in the cold condition. Without this clearance the valve could be held slightly open when hot, causing compression loss and burnt valve seats.

Question 39Engine Systems and Components

A four-cylinder four-stroke engine has a firing interval of:

  1. 180 degrees of crankshaft rotation Correct answer.
  2. 90 degrees of crankshaft rotation
  3. 720 degrees of crankshaft rotation
  4. 360 degrees of crankshaft rotation

Explanation

Each cylinder fires once in two revolutions, that is 720 degrees of crankshaft rotation. Dividing 720 degrees by four cylinders gives an even firing interval of 180 degrees.

Question 40Engine Systems and Components

An engine has a bore of 80 mm and a stroke of 90 mm. Using pi = 3.14, its swept volume per cylinder is closest to:

  1. 565 cc
  2. 226 cc
  3. 904 cc
  4. 452 cc Correct answer.

Explanation

Swept volume equals the cross-sectional area of the bore multiplied by the stroke. Area is 3.14 x 40 mm x 40 mm = 5024 mm squared, and multiplying by the 90 mm stroke gives about 452,160 cubic mm, that is roughly 452 cc.

Question 41Engine Systems and Components

The compression ratio of an engine is defined as the ratio of:

  1. Swept volume to clearance volume
  2. Total cylinder volume to clearance volume Correct answer.
  3. Bore to stroke
  4. Clearance volume to total cylinder volume

Explanation

Compression ratio compares the volume above the piston at bottom dead centre with the volume above it at top dead centre. The larger volume is the swept volume plus the clearance volume, and the smaller is the clearance volume alone.

Question 42Engine Systems and Components

In a water-cooled engine, the thermostat is provided to:

  1. Keep the coolant pressure below atmospheric
  2. Regulate coolant flow so the engine warms up quickly and stays at operating temperature Correct answer.
  3. Remove air bubbles from the cooling system
  4. Circulate the coolant through the radiator

Explanation

The thermostat stays closed while the coolant is cold, so the engine warms up quickly, and then opens progressively to admit coolant to the radiator. In this way it holds the engine near its designed operating temperature.

Question 43Engine Systems and Components

The valve overlap in an engine refers to the period when:

  1. Both valves of a cylinder are closed at the same time
  2. The exhaust valve remains closed during the exhaust stroke
  3. Both valves of a cylinder are open at the same time Correct answer.
  4. The inlet valve is open during the power stroke

Explanation

Valve overlap occurs near top dead centre at the end of the exhaust stroke, when the inlet valve has already opened and the exhaust valve has not yet closed. It helps use the outgoing gas flow to draw in a fresh charge.

Question 44Engine Systems and Components

A radiator cap marked 0.9 bar performs its main safety function by:

  1. Measuring the coolant temperature
  2. Raising the boiling point of the coolant by keeping the system under pressure Correct answer.
  3. Preventing coolant from circulating when the engine is cold
  4. Filtering the coolant as it passes through

Explanation

By holding the cooling system at a pressure above atmospheric, the cap raises the boiling point of the coolant and so reduces the risk of boiling at high engine temperatures. Its relief valve also releases excess pressure to protect the radiator and hoses.

Question 45Engine Systems and Components

When checking the valve clearance of an overhead-valve engine, the correct time to measure is when the valve is:

  1. Fully closed on the base circle of the cam Correct answer.
  2. At maximum lift
  3. Fully open on the base circle of the cam
  4. Partly open during overlap

Explanation

Valve clearance is measured when the follower is on the base circle of the cam and the valve is fully closed. At any other position the cam lift is partly or fully applied, and the measured gap will be meaningless.

Question 46Engine Systems and Components

The main function of piston rings is to:

  1. Connect the piston to the connecting rod
  2. Seal the combustion chamber, control oil and transfer heat to the cylinder wall Correct answer.
  3. Operate the inlet and exhaust valves
  4. Balance the crankshaft

Explanation

Compression rings seal the gases in the combustion chamber, oil-control rings scrape excess oil from the bore, and both help conduct heat from the piston to the cylinder wall. All three duties are essential to efficient engine operation.

Question 47Engine Systems and Components

Blue-grey smoke from the exhaust of a running petrol engine most often indicates:

  1. An excessively lean mixture
  2. Too rich an air-fuel mixture
  3. Burning of lubricating oil in the combustion chamber Correct answer.
  4. Water entering the exhaust system

Explanation

Blue-grey smoke is characteristic of oil being burned in the cylinders, typically from worn rings, worn valve guides or failed stem seals. Black smoke points to a rich mixture, while white vapour usually indicates water or coolant.

Question 48Engine Systems and Components

A compression test on a petrol engine gives a low reading on one cylinder, and the reading improves when a little oil is added through the spark plug hole. This most likely indicates:

  1. Worn piston rings or cylinder bore Correct answer.
  2. Incorrect ignition timing
  3. A leaking inlet valve
  4. A blown head gasket between two cylinders

Explanation

Oil temporarily seals the gap between the rings and the bore, so the compression rises if the rings or bore are worn. If the reading stays low after adding oil, the leak is more likely at a valve or gasket.

Question 49Engine Systems and Components

The purpose of the condenser (capacitor) connected across the contact points in a conventional ignition system is to:

  1. Reduce the battery voltage supplied to the coil
  2. Suppress arcing at the points and help collapse the primary current quickly Correct answer.
  3. Advance the ignition timing as engine speed rises
  4. Increase the spark duration at low engine speeds

Explanation

The condenser forms a tuned circuit with the primary winding so that the primary current falls very rapidly when the points open, giving a high secondary voltage. It also absorbs the arc that would otherwise burn the contact points.

Question 50Engine Systems and Components

In a turbocharged diesel engine, the wastegate is used to:

  1. Cool the compressed air before it enters the engine
  2. Increase the compression ratio at high load
  3. Limit boost pressure by bypassing exhaust gas around the turbine Correct answer.
  4. Lubricate the turbocharger bearings

Explanation

The wastegate opens when boost reaches the set value and diverts part of the exhaust flow around the turbine wheel. This limits the turbine speed and boost pressure, protecting the engine from over-boosting.