AC Theory

Question 1

What direction does AC travel through a conductor?

Answer 1

Both (it alternates)

Question 2

Name 2 advantages of AC over DC.

Answer 2

1. Wiring and equipment can be made much lighter
2. Its easier to transform

Question 3

The speed at which AC changes direction is called?

Answer 3

Frequency

Question 4

The level to which the voltage or current rises to is called?

Answer 4

Amplitude

Question 5

How are AC cycles per second expressed?

Answer 5

Hertz

Question 6

What are the values of the ships main electrical supplies?

Answer 6

• 3 phase
• 450 volts,
• 60 Hertz

Question 7

What is the frequency equation?

Answer 7

Time (seconds) = 1/Frequency

Question 8

What is the units of inductance

Answer 8

milli-Henries (mH) and micro-Henries (µH)

Henry (H)

Question 9

Label diagram

Answer 9

Question 10

What is frequency?

Answer 10

The number of cycles that are completed in 1 second.

expressed as Hertz

The time taken to complete one cycle is called the period.

Question 11

When a length of wire is formed into a coil what does it become?

Answer 11

A Basic inductor (Inductance)

Question 12

What is the unit of measurement for inductance?

Answer 12

• Henry (H)
• milli-Henries (mH) one thousandth of a henry.
• micro-Henries (uH) one millionth of a henry.