Deck 7: Alternating Current

Question 1

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

Answer 1

False

Question 2

What is the unit used to measure inductance?

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

Answer 2

B

Question 3

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

Answer 3

B

Question 4

Current ____ voltage in an inductor.

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

Question 5

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

Question 6

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

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

Question 7

What is one example of negative power?

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

Question 8

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

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

Question 9

Impedance is calculated by dividing ____ by ____.

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

Question 10

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

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

Question 11

The insulating material in a capacitor is called the ____.

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

Question 12

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

Question 13

A noninductive coil has high ____ and no inductance.

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

Question 14

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

Question 15

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