ASVAB Automotive Information Practice Questions Answered Correctly Latest Version () Already Passed

ASVAB Automotive Information Practice Questions Answered Correctly Latest Version () Already Passed What three things must be present before combustion can occur in an internal combustion engine? - Answers air; fuel; a heat source What function does a cylinder perform? - Answers A cylinder forms a guide for the piston, allowing the piston to move up and down as the engine completes its cycle What are the four strokes of a four-stroke cycle from first to last? - Answers intake; compression; power; exhaust What are TDC and BDC? - Answers top dead center; bottom dead center. Travel from TDC to BDC and back constitutes one stroke. What are the three most common cylinder arrangements in internal combustion engines? - Answers inline; horizontally opposed (flat); V-type In a double overhead cam arrangement, what does each cam do? - Answers One cam operates the exhaust valves; the other operates the intake valves What are the two advantages of a four-valve cylinder head over a two-valve cylinder head? - Answers higher engine operating speeds; more complete combustion of the air-fuel mixture 25 degrees BTDC (before top dead center) is an example of ________ ignition timing. - Answers advanced What are two likely causes of pre -ignition? - Answers a glowing spark plug; a hot piece of carbon What is the most likely cause of engine "knock"? - Answers The air-fuel mixtures explodes (detonates) rather than burns, often due to a lean air-fuel mixture What is the function of the radiator? - Answers to transmit heat from the coolant to the outside air What is the optimal range of pressure in a cooling system? - Answers 9 to 16 psi (pounds per square inch) When the thermostat is ______, coolant does not pass through the radiator? - Answers closed What are the two main components of engine oil? - Answers Base oil; additive package Which area of the engine is most reliant on lubrication? - Answers The reciprocating assembly (pistons, connecting rods, crankshaft) The most common types of fuel injection systems are ______ and _____. - Answers Multi port fuel injection; direct injection What function does the distributor perform? - Answers The distributor is responsible for timing the ignition spark and distributing it to the correct cylinder What parts have been eliminated in coil-on-plug ignition systems? - Answers Spark plug wires What is the basic function of the drive train system? - Answers to transmit power from the engine to the wheels The trans axle in a front-wheel drive vehicle combines which two components that are normally distinct in a rear-wheel drive vehicle? - Answers Transmission; drive axle The ____ allows the left and right wheels to turn at differently speeds while cornering - Answers Differential What does an automatic transmission use instead of a clutch? - Answers A torque converter The____ generation the fluid pressure to operates the brake assemblies at the wheels. - Answers master cylinder What five function does an engine's lubrication system preform? - Answers The lubrication system lubricates, cools, seals. cleans, and quiets What is the function of the intake valve in an internal combustion engine? - Answers The intake valve allows the air-fuel mixture to be drawn into the combustion chamber. What are a car's water jackets? - Answers Water jackets are hollow sections of the engine block through which coolant flows What does an intake manifold do? - Answers An intake manifolds is the structure that delivers air to the intake ports of the engine's cylinders Define stoichiometric ratio - Answers The stoichiometric ratio is the ideal air-fuel mixture for insertion into the engine cylinder. For gasoline engines, this is 14.7:1 by weight. between the drive axle and the CV joints is a short drive shaft called the _______ - Answers Half shaft Spent fuel gases exit the cylinder and pass into the ____ - Answers Exhaust manifold Diesel engines lack a ______ (a common element in gasoline-burning engines). - Answers Spark-ignition system Does an alternator produce DC or AC power? - Answers AC What does a camshaft do? - Answers A camshaft opens and closes the cylinders' intake and exhaust valves. The low-voltage winding in a car's ignition system is called the _______. - Answers primary coil winding What is chiefly responsible for generating fluid pressure to operate a car's brakes? - Answers the master cylinder What does a fuel rail do? - Answers A fuel rail delivers fuel under pressure to the engine's fuel injectors. Brakes work through _____ pressure - Answers hydraulic (or fluid) The camshaft is driven by the crankshaft by means of a ______ - Answers Timing belt or timing chain Where is the oil filter positioned in an engine? - Answers The oil filter filters oil after it leaves the oil pump and before it circulates through the engine. ________ work by adjusting the brake pressure in each wheel depending on the wheel's speed - Answers Anti-lock brakes (ABS) Diesel engines employ ______ to ignite the air-fuel mixture - Answers a high compression ratio What is PCM? - Answers Powertrain control module - that is, a cars computer Engine coolant is usually composed of a mixture of ____% antifreeze and ___% water - Answers 50;50 The ____ matches engine speed to the desired speed of the vehicle - Answers transmission Internal combustion engines take ____ energy, convert it into ____ energy and then into _______ energy - Answers chemical; heat; mechanical Most internal combustion engines employ a ______-stroke cycle - Answers Four Define viscosity - Answers The viscosity of a liquid is its resistance to flow; liquids with higher viscosity are thicker and flow less easily What is the difference between disc brakes and drum brakes? - Answers In disc brakes, brakes pads on both sides of a rotating disc are pinched together to slow the disc's rotation. In drum brakes, brake shoes inside a rotating drum expand to make contact with the interior of the drum, slowing its motion A radiator cap has two valves: a(n) ____ valve and a(n) _____ valve. - Answers pressure; vacuum (or vaccum; pressure) Define engine block. - Answers the engine block is a framework in which the cylinders are