Question 1

Technician A says moving magnetic fields are a source of electrical energy in an automobile. Technician B says chemical reaction is the only source of electrical energy in an automobile. Who is correct?

Accepted Answer

Technician A is correct because moving magnetic fields in components like the alternator generate electrical energy. Technician B is incorrect because, besides chemical reactions in the battery, other sources like the alternator also contribute to electrical energy in an automobile.

Question 2

All the following parts are used as circuit protection EXCEPT:

Accepted Answer

Relays are used to control a high-power or high-voltage circuit with a low-power signal. They are not designed to protect circuits from overcurrent or short circuits, unlike fuses and circuit breakers which are specifically designed for circuit protection. Fuse links also serve a protective function similar to fuses.

Question 3

Technician A says late model cars use maxifuses instead of fusible links. Technician B says fusible links are normally found in the engine compartment near the battery. Who is correct?

Accepted Answer

Both statements are correct. Late model cars often use maxifuses instead of fusible links for high current protection, and fusible links are commonly located in the engine compartment near the battery to protect the electrical system.

Question 4

Technician A says the conventional theory of current flow states that current flows from negative to positive. Technician B says the electron current flow theory states that electrons move from negative to positive. Who is correct?

Accepted Answer

Technician B is correct. The electron current flow theory states that electrons move from negative to positive. Technician A is incorrect because the conventional current flow theory states that current flows from positive to negative.

Question 5

Technician A says when there is a complete path through the electrical circuit, the circuit is said to be open. Technician B says when the circuit path is broken or interrupted the circuit is said to be closed. Who is right?

Accepted Answer

An open circuit means the path is broken, preventing current from flowing, while a closed circuit means there is a complete path for current to flow. Both technicians' statements are incorrect.

Question 6

Technician A says current 14-volt systems are rated at 800 W to 1500 W. Technician B says a higher voltage system requires more amperage to produce the same wattage. Who is correct?

Accepted Answer

Technician A is correct because current 14-volt automotive electrical systems are indeed rated within the 800 W to 1500 W range. Technician B is incorrect because a higher voltage system requires less amperage to produce the same wattage, according to the formula Wattage = Voltage x Amperage.

Question 7

Which of the following is a source of energy in an automobile's electrical system?

Accepted Answer

Both the battery and the AC generator (alternator) are sources of energy in an automobile's electrical system. The battery provides electrical power to start the engine and power accessories when the engine is not running. The alternator generates electricity to recharge the battery and power the electrical system while the engine is running.

Question 8

Technician A says 42-volt automotive electrical systems can use smaller wires to supply the same amount of power to electrical accessories. Technician B says a 42-volt electrical system can kill you if your skin contacts exposed wiring. Who is correct?

Accepted Answer

Technician A is correct because using a higher voltage allows for the same power to be transmitted with less current, which means that smaller gauge wires can be used. Technician B is incorrect because, while a 42-volt system is more powerful than the traditional 12-volt systems found in most cars, it is still considered low voltage and is not generally capable of delivering a lethal shock under normal conditions.

Question 9

A _____ is an electromagnet with a movable core that converts electrical current into mechanical movement.

Accepted Answer

A solenoid is an electromagnet with a movable core, known as an armature, which converts electrical current into mechanical movement.

Question 10

In the formula E = I x R, the I represents_____.

Accepted Answer

The formula E = I x R is known as Ohm's Law, where E represents voltage, I represents current (measured in amperes), and R represents resistance (measured in ohms).

Question 11

Technician A says the amount of electricity produced by an AC generator depends on the strength of the magnetic field. Technician B says it depends on the speed at which the magnetic field moves past the wires. Who is correct?

Accepted Answer

Both the strength of the magnetic field and the speed at which the magnetic field moves past the wires influence the amount of electricity produced by an AC generator.

Question 12

Technician A says current will decrease with a decrease in resistance. Technician B says current will increase with an increase in resistance. Who is correct?

Accepted Answer

According to Ohm's Law, current is inversely proportional to resistance. Therefore, a decrease in resistance will increase current, and an increase in resistance will decrease current. Both technicians are incorrect.

Question 13

Which statement concerning series circuits is NOT true?

Accepted Answer

The total resistance in a series circuit is equal to the sum of the resistances of each load, not just the lowest resistance.

Question 14

In the formula E = I x R, the R represents_____.

Accepted Answer

In the formula E = I x R, which is Ohm's Law, R represents resistance, measured in ohms (Ω).

Question 15

In the formula E = I x R, the E represents _____.

Accepted Answer

The formula E = I x R is known as Ohm's Law, where E represents voltage, I represents current (in amperes), and R represents resistance (in ohms).

Question 16

Which of the statements concerning parallel circuits is NOT true?

Accepted Answer

In a parallel circuit, the voltage drop across each leg is the same and equals the total voltage, not the combined voltage drop of all legs. This is because each leg is directly connected across the power source.

Question 17

Switches are being discussed. Technician A says that "pole" refers to the number of output circuits. Technician B says that "throw" refers to the number of input circuits. Who is correct?

Accepted Answer

In the context of switches, "pole" refers to the number of separate circuits that the switch can control, not the number of output circuits specifically. "Throw" indicates the number of positions that each switch pole can connect to, not the number of input circuits. Therefore, both Technician A and Technician B are incorrect in their definitions.

Question 18

The amount of electricity produced in the vehicle's generator depends on _____.

Accepted Answer

The amount of electricity produced in a vehicle's generator depends on the strength of the magnetic field, the number of wires that are passed through the magnetic field, and the speed at which the magnetic field passes through the wires. These factors collectively influence the electromagnetic induction process, which is the principle behind the generation of electricity in such systems.

Question 19

The unit for measuring electrical pressure (force)is _____.

Accepted Answer

Electrical pressure, or force, is measured in volts. This unit quantifies the potential difference or electromotive force in an electrical circuit.

Question 20

Wire sizes are being discussed. Technician A says an AWG 20 gauge wire is larger than an AWG 22 gauge wire. Technician B says a metric 1.0 gauge wire is smaller than a metric .8 gauge wire.

Accepted Answer

Technician A is correct because in the American Wire Gauge (AWG) system, a lower gauge number means a larger wire diameter. Therefore, an AWG 20 gauge wire is indeed larger than an AWG 22 gauge wire. Technician B is incorrect because in metric wire sizes, a larger number indicates a larger diameter, so a metric 1.0 gauge wire is larger, not smaller, than a metric .8 gauge wire.

Quiz 15: Basics of Electrical Systems