Deck 7: Alternating Current

Question 1

What is one example of negative power?

A) a battery charging
B) current flowing through a resistor
C) voltage across a capacitor
D) impedance of an inductor

Answer 1

A

Question 2

Impedance is calculated by dividing ____ by ____.

A) power; voltage
B) voltage; power
C) current; voltage
D) voltage; current

Answer 2

D

Question 3

What is the unit of measurement for inductance?

A) gilbert
B) henry
C) ohm
D) farad

Answer 3

B

Question 4

A noninductive coil has high ____ and no inductance.

A) resistance
B) reactance
C) current
D) frequency

Question 5

The ____ value of an alternating current will produce the same heating effect as a specific value of a steady direct current.

A) conversion
B) instantaneous
C) effective
D) average

Question 6

In a purely capacitive circuit, the current will lead the voltage by ____ degrees.

A) -90
B) 90
C) 180
D) 360

Question 7

Current ____ voltage in an inductor.

A) lags
B) leads
C) is equal to
D) is always in phase with

Question 8

In mutual induction, there is an electrical connection between two or more coils.

Question 9

The amount of voltage produced by a coil rotating in a magnetic field depends, in part, upon the strength of the magnetic field.

Question 10

Three-phase systems provide separate voltages that are ____ electrical time degrees apart.

A) 90
B) 120
C) 180
D) 360

Question 11

Electromagnetic induction can be accomplished in two different ways: by moving a magnetic field across a coil, or a coil moving through the magnetic field.

Question 12

The insulating material in a capacitor is called the ____.

A) shield
B) plate
C) diaphragm
D) dielectric

Question 13

In a DC circuit, a capacitor allows the current to flow only until the charge on the capacitor is ____.

A) greater than the applied voltage
B) equal to the applied voltage
C) less than the applied voltage
D) zero

Question 14

The ease with which the voltage can be raised and lowered makes DC ideal for transmission purposes.

Question 15

Vector diagrams, drawn to scale, can be used to determine average power values.