Auto and Shop Information: Automotive Systems Flashcards
6 cards from real AFCT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Auto and Shop Information: Automotive Systems flashcards as text
What is the primary function of a catalytic converter in an automobile's exhaust system?
Answer: To convert harmful exhaust gases into less toxic emissions
A catalytic converter uses chemical catalysts (platinum, palladium, rhodium) to convert harmful pollutants like carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful carbon dioxide, water vapor, and nitrogen.
In a hydraulic braking system, what happens when you press the brake pedal?
Answer: Hydraulic pressure is transmitted equally through brake fluid to all brake calipers
Pressing the brake pedal activates the master cylinder, which pressurizes brake fluid. Per Pascal's law, this hydraulic pressure is transmitted equally through the brake lines to calipers or wheel cylinders at each wheel.
What component in an automatic transmission allows the engine to idle without stalling when the vehicle is stopped?
Answer: The torque converter
The torque converter is a fluid coupling that connects the engine to the transmission. It allows the engine to spin independently of the transmission at idle, preventing stalling when the vehicle is stationary.
What is the purpose of the alternator in a vehicle's electrical system?
Answer: To convert mechanical energy into electrical energy to charge the battery and power accessories
The alternator converts mechanical energy from the engine's serpentine belt into alternating current (AC) electrical energy, which is then rectified to direct current (DC) to charge the battery and power the vehicle's electrical systems.
What does the thermostat in a vehicle's cooling system control?
Answer: The flow of coolant between the engine and radiator based on temperature
The thermostat is a temperature-sensitive valve that remains closed when the engine is cold, allowing it to warm up quickly. Once the coolant reaches the set temperature (typically 195-220°F), it opens to allow coolant flow to the radiator for cooling.
In a four-stroke gasoline engine, during which stroke does combustion occur?
Answer: Power stroke
Combustion occurs at the beginning of the power stroke. After the air-fuel mixture is compressed during the compression stroke, the spark plug ignites it, and the expanding gases push the piston down during the power stroke.