3.13

Question 1

What are the two differentiating characteristics of AC?

Answer 1

• the amount of voltage changes due to time

- it’s direction (polarity) changes regularly

Question 2

What is the RMS value?

Answer 2

The root mean square value - used when comparing AC to DC

Question 3

What must be done to a peak value from an AC current to find the correct DC operating voltage?

Answer 3

Multiply the peak value by 0.707

Question 4

What must be done to a DC operating value (RMS) to find the correct AC operating peak voltage?

Answer 4

Multiply the RMS value by 1.414

Question 5

What is the equation for frequency? F(Hz)

Answer 5

1/T (one full sine wave)

Question 6

What is a three phase generator?

Answer 6

Three generators packed into one housing with each coil displaced at an angle of 120°

Question 7

How many different voltages can occur in a 3 phase generator?

Answer 7

Two

• 115V for single phase
• 200V from phase to phase

Question 8

What is the main advantage of a 3-phase generator?

Answer 8

A continuous output power which causes less strain to the bearings

Question 9

For Common AC it is said that

Answer 9

Change repeats itself continually
Average is zero
It is a sine curve

Question 10

Non Sinusoidal AC voltages and currents

Answer 10

Do not show the sinusoidal waveform in voltage time or current time diagrams.