Question 1

RTV silicone sealer should be applied to a wire repair to seal out water.

Accepted Answer

False

Question 2

All types of wire with identical gauge numbers (e.g. 12 AWG) always have the same thickness of insulation material.

Accepted Answer

The gauge number refers to the diameter of the wire, not the thickness of the insulation, which can vary depending on the wire's intended use and specifications.

Question 3

12V is measured across a switch in a 12V electric circuit. This indicates the switch must be closed (in the ON position).

Accepted Answer

If 12V is measured across a switch, it indicates that the switch is open (in the OFF position), as the voltage drop occurs across the open switch.

Question 4

The common terminal of an ISO relay (terminal 30) is always connected to chassis ground.

Accepted Answer

Terminal 30 of an ISO relay is typically connected to a constant power source, not necessarily to chassis ground.

Question 5

A technician measures an open circuit (infinite resistance) between an ISO relay normally-open terminal 87 and the normally-closed terminal 87A. This indicates the relay should be fully-functional.

Accepted Answer

An open circuit between terminal 87 and 87A indicates that the relay is not functioning properly, as there should be continuity when the relay is in the normally-closed position.

Question 6

Relay coil suppression prevents the relay from drawing too much current.

Accepted Answer

Relay coil suppression is used to prevent voltage spikes when the relay is de-energized, not to limit current draw.

Question 7

A relay can be felt and heard to "click" when energized. This indicates the relay is fully functional.

Accepted Answer

The clicking sound indicates that the relay coil is energized and the contacts are moving, but it does not guarantee that the relay is fully functional or that the contacts are making a proper electrical connection.

Question 8

Referring to figure shown below, the left side back-up lamp is very dim but the right side back-up lamp is bright when the transmission is in reverse. The back-up lamp switch is not the likely cause of the dim left side back-up lamp.

Accepted Answer

The answer of Referring to figure shown below, the left...

Question 9

Which wire would have the largest diameter conductor?

Accepted Answer

4-0 AWG (0000 AWG) has the largest diameter among the given options, as AWG sizes decrease in number as the wire diameter increases.

Question 10

Technician A says that 10 feet (3 m) of 10 AWG wire has less resistance than 20 feet (6 m) of 10 AWG wire. Technician B says that 10 feet (3 m) of 10 AWG wire has more resistance than 10 feet (3 m) of 20 AWG wire. Who is correct?

Accepted Answer

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Since the cross-sectional area of 10 AWG wire is larger than that of 20 AWG wire, 10 feet of 10 AWG wire will have less resistance than 20 feet of 10 AWG wire.

Question 11

A momentary-contact normally-open switch would likely be used to control which type of device?

Accepted Answer

A momentary-contact normally-open switch is typically used for devices that require temporary activation, such as a horn, which is only activated while the switch is pressed.

Question 12

Technician A says that a normally-closed switch is always closed when all conditions are normal. Technician B says that a normally-open switch is always open when all conditions are normal. Who is correct?

Accepted Answer

The answer of Technician A says that a normally-closed switch...

Question 13

Which is the following is an electrical load?

Accepted Answer

All of the options (headlamp, blower motor, and resistor) can be considered electrical loads as they consume electrical power in a circuit.

Question 14

Technician A says that the primary purpose of a circuit protection device is to protect the electrical load, such as a headlamp. Technician B says that it is ok to use a larger fuse if the existing fuse keeps blowing. Who is correct?

Accepted Answer

The primary purpose of a circuit protection device is to protect the wiring and prevent fires, not the electrical load itself. Using a larger fuse than specified can lead to overheating and potential damage or fire, so it is not advisable.

Question 15

Which of the following is a true statement?

Accepted Answer

Inrush current is indeed a high level of current drawn by devices like motors or transformers when they are first switched on. The other statements are incorrect: a 10A fuse may not blow immediately at slightly over 10A due to its time-delay characteristics, and power dissipation depends on both current and voltage, so doubling current doesn't always double power.

Question 16

A technician measures a circuit resistance with an ohmmeter and finds 1 ohm of resistance. He then connects a 12V battery to the circuit and measures a current of 1A. Per Ohm's law, he expected 12A of current to flow. What is a likely reason for the discrepancy?

Accepted Answer

The answer of A technician measures a circuit resistance with...

Question 17

Technician A says that a headlamp that does not illuminate due to high circuit resistance would be described as a "short". Technician B says that a blown fuse or tripped circuit breaker is always caused by a short to ground. Who is correct?

Accepted Answer

Technician A is incorrect because high circuit resistance would cause a "high resistance" issue, not a "short". Technician B is incorrect because a blown fuse or tripped circuit breaker can also be caused by an overload, not just a short to ground.

Question 18

Referring to the figure shown below, a blown fuse F5 would likely be caused by which of the following?

Accepted Answer

The answer of Referring to the figure shown below, a...

Question 19

Referring to the following figure, the mirror heat does not function on either side of the truck, but the back-up lamps illuminate with the transmission in reverse. Which is the least likely cause of the inoperative mirror heat?

Accepted Answer

The answer of Referring to the following figure, the mirror...

Question 20

The three types of shorted circuits include a short to ground, a short to battery positive, and _______?

Accepted Answer

A wire-to-wire short is another type of short circuit where two wires that should not be connected come into contact, causing a short circuit.

Quiz 4: Electrical Components