Key Topic 1: Electrical Elements

Question 1

3-1A1: The product of the readings of an AC voltmeter and AC ammeter is called:

A. Apparent power.
B. True power.
C. Power factor.
D. Current power.

Answer 1

A. Apparent power.

Question 2

3-1A2: What is the basic unit of electrical power?

A. Ohm.
B. Watt.
C. Volt.
D. Ampere.

Answer 2

B. Watt.

Question 3

3-1A3: What is the term used to express the amount of electrical energy stored in an electrostatic field?

A. Joules.
B. Coulombs.
C. Watts.
D. Volts.

Answer 3

A. Joules.

Question 4

3-1A4: What device is used to store electrical energy in an electrostatic field?

A. Battery.
B. Transformer.
C. Capacitor.
D. Inductor.

Answer 4

C. Capacitor.

Question 5

3-1A5: What formula would determine the inductive reactance of a coil if frequency and coil inductance are known?

A. XL = πfL.
B. XL = 2πfL.
C. XL = 1 / 2πfC.
D. XL = 1 / R2+X2.

Answer 5

B. XL = 2πfL.

Question 6

3-1A6: What is the term for the out-of-phase power associated with inductors and capacitors?

A. Effective power.
B. True power.
C. Peak envelope power.
D. Reactive power.

Answer 6

D. Reactive power.