AFCT Auto and Shop Information: Automotive Systems 2

Question 1

What is the primary function of a catalytic converter in an automobile's exhaust system?

Accepted Answer

To convert harmful exhaust gases into less toxic emissions

Answer

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.

Question 2

In a hydraulic braking system, what happens when you press the brake pedal?

Accepted Answer

Hydraulic pressure is transmitted equally through brake fluid to all brake calipers

Answer

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.

Question 3

What component in an automatic transmission allows the engine to idle without stalling when the vehicle is stopped?

Accepted Answer

The torque converter

Answer

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.

Question 4

What is the purpose of the alternator in a vehicle's electrical system?

Accepted Answer

To convert mechanical energy into electrical energy to charge the battery and power accessories

Answer

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.

Question 5

What does the thermostat in a vehicle's cooling system control?

Accepted Answer

The flow of coolant between the engine and radiator based on temperature

Answer

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.

(AFCT) Armed Forces Classification Test Practice Test

(AFCT) Armed Forces Classification Test Practice Test

AFCT Auto and Shop Information: Automotive Systems 2