Deck 7: Alternating Current Power Distribution and Voltage Systems

Question 1

What are the disadvantages of using direct current to supply consumers with their electrical needs?

Answer 1

Transmission for a long distance is impossible without using generators to boost the power. The inability to raise and lower DC voltages and the need to use large transmission equipment are other problems.

Question 2

What are the main components of an alternator?

Answer 2

The alternator is made up of a winding, or set of windings, called the stator and a rotating magnet called the rotor.

Question 3

240-Volt-Three-Phase-60-Hertz ____________________ system is used in structures that require a large supply to motors and other three-phase equipment.

Answer 3

delta

Question 4

What is the difference between single-phase and three-phase current?

Question 5

What is reactance?

Question 6

In the United States, the common frequency is 50 Hz.

Question 7

The ____________________ of an AC circuit is the number of currents alternating at different time intervals in the circuit.

Question 8

One cycle occurs when the rotor, or conductor, cuts the magnetic field of a north pole and south pole.

Question 9

The effective voltage of an alternating current circuit is ____________________ times its peak voltage.

Question 10

Direct current is an electron flow in only one direction.

Question 11

What is capacitive reactance?

Question 12

Because alternating current starts at zero, reaches a peak, and then returns to zero, there is always a variation in voltage and an effective value has to be determined.

Question 13

What is inductance?

Question 14

There are two types of electric current: direct current and ____________________ current.

Question 15

What is the power factor and how is it usually expressed mathematically?

Question 16

The frequency of alternating current is the number of complete cycles that occur in a minute.

Question 17

The frequency is known as ohms but many times, it is referred to as cycles.

Question 18

Alternating current reaches a peak at ____________________ electrical degrees, also known as the peak voltage.

Question 19

What is inductive reactance?

Question 20

Alternating current is produced by a(n) ____________________.