Key Topic 6: Electrical Measurements

Question 1

3-6A1: An AC ammeter indicates:

A. Effective (TRM) values of current.
B. Effective (RMS) values of current.
C. Peak values of current.
D. Average values of current.

Answer 1

B. Effective (RMS) values of current.

Question 2

3-6A2: By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak voltage value?

A. 0.707
B. 0.9
C. 1.414
D. 3.14

Answer 2

C. 1.414

Question 3

3-6A3: What is the RMS voltage at a common household electrical power outlet?

A. 331-V AC.
B. 82.7-V AC.
C. 165.5-V AC.
D. 117-V AC.

Answer 3

D. 117-V AC.

Question 4

3-6A4: What is the easiest voltage amplitude to measure by viewing a pure sine wave signal on an oscilloscope?

A. Peak-to-peak.
B. RMS.
C. Average.
D. DC.

Answer 4

A. Peak-to-peak.

Question 5

By what factor must the voltage measured in an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?

A. 0.707
B. 1.414
C. 0.9
D. 3.14

Answer 5

C. 0.9

Question 6

3-6A6: What is the peak voltage at a common household electrical outlet?

A. 234 volts.
B. 117 volts.
C. 331 volts.
D. 165.5 volts.

Answer 6

D. 165.5 volts.