Deck 3: Physics for Electricity

Question 1

The magnetic attraction or repulsion force that exists between two magnets increases at a nonlinear rate as the distance between two magnets decreases.

Answer 1

True

Question 2

Like magnetic poles repel each other; unlike magnetic poles attract each other.

Answer 2

True

Question 3

Conductors that are carrying current are compelled (want) to move out of a weaker magnetic field into a stronger magnetic field.

Answer 3

False

Question 4

Cutting magnetic lines of force with a conductor causes a voltage to be induced in the conductor.

Question 5

The more rapid the decrease in the current flow through an inductor, the higher the amplitude of the reverse-polarity voltage that is developed across the inductor.

Question 6

A transformer can be used without any additional devices to step-up 12V DC to 24V DC.

Question 7

Electric fields are the result of current flow; magnetic fields are the result of a difference in potential (voltage) between two points.

Question 8

Which device would draw the most current?

A) 60W household light bulb supplied with 120V AC
B) 60W truck low beam headlamp supplied with 12V
C) An inductor with a resistance of 120 ohms supplied with 12V
D) All of the above would draw the same amount of current

Question 9

Technician A says that reluctance can be measured using an ohmmeter. Technician B says that inductance can be measured using an ohmmeter. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 10

Which of the following would NOT be used as a dielectric material?

A) Air
B) Glass
C) Copper
D) Paper

Question 11

Technician A says that a capacitor stores energy in the form of an electric field. Technician B says that an inductor stores energy in the form of a magnetic field. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 12

Which is the correct equation for Watt's law?

A) Watts/Amps = Volts
B) Volts × Amps = Watts
C) Watts/Volts = Amps
D) All of the above are valid expressions of Watt's law.

Question 13

A negative voltage spike as the result of interruption of current flow through an inductor is caused by which of the following?

A) Suppression
B) Capacitance
C) CEMF
D) Reluctance

Question 14

Referring to the circuit shown below, technician A says that 12V would be instantly dropped across the capacitor when the switch is moved from position 2 to position 1. Technician B says that the voltage dropped across the capacitor would never exceed 6V. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 15

Which of the following is a true statement regarding the circuit shown below?

A) The resistance value (ohms) of the resistor influences the amount of time for the capacitor to charge.
B) The capacitance value (farads) influences the amount of time for the capacitor to charge.
C) Moving the switch from position 1 to position 3 would cause the direction of current flow through the resistor to reverse.
D) All of the above are true statements.

Question 16

Which are the correct units for the measurement of inductance?

A) Farads
B) Ohms
C) Lenz
D) Henries

Question 17

Technician A says that the more rapid the decrease in the current flow through an inductor, the higher the amplitude of the reverse-polarity voltage that is developed across the inductor. Technician B says that an oscilloscope can be used to display a changing voltage with respect to time. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 18

Which device would likely contain a capacitor?

A) Entertainment radio
B) Alternator
C) Electronic engine control module
D) All of the above would likely contain a capacitor.

Question 19

The three factors that determine the amount of capacitance of a capacitor include the area of the plates, the distance between the plates and _______?

A) the reluctance of the material between the plates
B) the number of amp-turns in the dielectric constant
C) the dielectric constant of the material between the plates
D) the CEMF of the capacitance

Question 20

The three factors that determine the amount of inductance of an inductor include the number of loops making up the coil, the dimensions of the coil, and _______?

A) the reluctance of the material in the coil
B) the number of amp-turns in the dielectric constant
C) the dielectric constant of the material between the coils
D) the CEMF of the inductance