Question 1

Switches are the least common means of providing control of electrical current flow to an accessory.

Accepted Answer

Switches are the most common means of providing control of electrical current flow to an accessory.

Question 2

Voltage drop can exist on the power side as well as the ground side of an electrical circuit.

Accepted Answer

This statement is true. Voltage drop can occur on both the power side and the ground side of an electrical circuit.

Question 3

In a PNP transistor both the base and the collector must be negative in respect to the emitter for current to flow through the emitter to the collector.

Accepted Answer

In a PNP transistor, the emitter is positive with respect to both the base and the collector for current to flow from the emitter to the collector.

Question 4

Direction of current flow through a diode can be identified by a band around the cathode end.

Accepted Answer

A band around the cathode end of a diode indicates the direction of current flow, which is from anode to cathode.

Question 5

Circuit protectors are usually found on the negative side of the circuit.

Accepted Answer

Circuit protectors can be found on either the positive or negative side of a circuit, depending on the design and application.

Question 6

Technician A says an open circuit has no breaks in the path and current will flow. Technician B says in a closed circuit the circuit path is broken. Who is correct?

Accepted Answer

Both technicians have made incorrect statements. An open circuit has a break in the path and current cannot flow. A closed circuit, on the other hand, has a complete path for current to flow.

Question 7

The load current flowing through a transistor passes through the emitter and the base circuit.

Accepted Answer

The load current in a transistor primarily flows through the collector and the emitter, not through the base circuit. The base circuit controls this current, but does not carry the load current itself.

Question 8

The trigger selection tells the lab scope when to begine to display a waveform.

Accepted Answer

The trigger selection is an important function of a lab scope as it tells the scope when to start displaying the waveform.

Question 9

A voltmeter placed across the terminals of an inoperative electric window motor indicates 12 volts when the window switch is depressed. Technician A says the window ground circuit may be faulty. Technician B says the window power feed circuit may be faulty. Who is correct?

Accepted Answer

The answer of A voltmeter placed across the terminals of...

Question 10

A short circuit will result when a current carrying wire is grounded before reaching the load.

Accepted Answer

A short circuit occurs when a current-carrying wire is connected to a low-resistance path (such as a ground) before it reaches the intended load. This creates a sudden surge of current that can cause damage to the circuit and potentially start a fire.

Question 11

Technician A says if a fuse blows as soon as it is installed, a short to ground is indicated. Technician B says the component will not turn off if the short to ground is on the ground side of the load component but before a grounding switch. Who is correct?

Accepted Answer

Both technicians are correct. Technician A is correct in stating that a fuse blowing immediately upon installation typically indicates a short to ground, as this suggests an unintended direct path to ground is allowing excessive current to flow, causing the fuse to blow. Technician B is correct in stating that if the short to ground occurs on the ground side of the load component but before a grounding switch, the component will not turn off because the short provides a continuous path to ground, bypassing the control that the switch would normally provide.

Question 12

Technician A s ays both an ohmmeter and a self-powered test light may be used to test for continuity. Technician B says both may be used to test fuses. Who is correct?

Accepted Answer

Both Technician A and B are correct. An ohmmeter and a self-powered test light can be used to test for continuity. Similarly, both can also be used to test fuses.

Question 13

What will a Zener diode do at breakdown voltage?

Accepted Answer

At breakdown voltage, a Zener diode will allow reverse current to flow in order to maintain a constant voltage. This is the purpose of a Zener diode, to regulate voltage by allowing reverse current to flow when the voltage reaches a specific threshold.

Question 14

Technician A says a fuse will automatically reset after the cause of the overload is repaired. Technician B says when an overload occurs, the protection device creates an open. Who is correct?

Accepted Answer

Technician B is correct because when an overload occurs, a fuse or circuit breaker (protection device) will create an open circuit to protect the electrical system. Fuses do not automatically reset; they must be replaced if blown. Circuit breakers can be reset manually, but this is not an automatic process following repair of the overload cause.

Question 15

An inoperative horn is being tested. A DVOM placed across the relay load contact terminals indicates battery voltage when the horn button is pushed. A "click" is heard from the relay when the button is pushed. Technician A says the relay is bad. Technician B says the relay coil circuit is bad. Who is correct?

Accepted Answer

The relay clicking indicates the coil circuit is functioning, but battery voltage across the load contact terminals without the horn operating suggests the relay is not completing the circuit properly, pointing to a faulty relay.

Question 16

Technician A says a Zener diode is an excellent component for regulating voltage. Technician B says when a circuit is opened suddenly to a large load, such as a coil, installing a clamping diode provides a bypass for the electrons. Who is correct?

Accepted Answer

Technician A is correct in stating that a Zener diode is an excellent component for regulating voltage as it can maintain a constant voltage output regardless of changes in current or input voltage. 
Technician B is correct in stating that installing a clamping diode provides a path for the current to flow when a circuit is opened suddenly to a large load, protecting the circuit components from a sudden voltage spike. Therefore, both technicians are correct.

Question 17

The frame of the vehicle is normally attached to the negative battery post.

Accepted Answer

The frame of the vehicle is typically connected to the negative battery post to establish a ground connection, which completes the electrical circuit for the vehicle's electrical system.

Question 18

The leads of a DMM with a diode check function are placed across the terminals of a diode and then reversed. A 0.6 volt reading is obtained in both directions. Technician A says this means the diode is shorted. Technician B says this means the diode is acceptable. Who is correct?

Accepted Answer

A diode should only conduct in one direction, showing a voltage drop (typically around 0.6V for silicon diodes) in the forward-biased direction and showing OL (overload, indicating very high resistance) in the reverse-biased direction. A 0.6V reading in both directions indicates the diode is shorted, as it is conducting in both directions, which aligns with Technician A's statement.

Question 19

Technician A says a stepped resistor should be disconnected from the circuit before testing it with an ohmmeter. Technician B says that a relay may be tested while it is connected to the circuit. Who is correct?

Accepted Answer

The answer of Technician A says a stepped resistor should...

Question 20

Throttle position sensors are variable resistors with two wires attached.

Accepted Answer

Throttle position sensors can be variable resistors, but they typically have three wires attached: a 5V reference input, a ground, and a signal output to the ECU (Engine Control Unit), not just two.

Quiz 3: Electrical and Electronic Componentsbasic Electrical Troubleshooting and Service