Electrical level 2 module 1 alternating current
1. What is the step-down turns ratio of a transformer with 200 turns in the
primary and 100 turns in the secondary?: 2:1
2. Opening the secondary circuit of a current transformer under load will
cause a dangerous level of: induced high voltage
3. What is the frequency of an AC waveform that completes 20 cycles per half
second?: 40Hz
4. A circuit has a peak voltage of 275V. What is the average voltage value?:
175V
5. Each of three equal capacitors in series has: one-third the applied voltage
6. The formula for inductive reactance is: XL = 2ÀfL
7. What is the current flow in a purely resistive AC circuit if the resistance is
15 ohms and the voltage is 150V?: 10A
8. If the area of the plates of a capacitor is increased, the amount of
capacitance: increases
9. The self-induced voltage across an inductance is produced by a change
in: current with respect to time
10. A 30-microfarad capacitor is in parallel with a 15-microfarad capacitor. The
total capacitance is: 45
11. One type of nonsinusoidal waveform is the: square wave
12. According to the power triangle, the apparent power is: greater than the
true power
13. A device that uses electromagnetic induction to transfer electrical energy
from one circuit to another is a(n): transformer
14. If a transformer has 200 turns in the primary, 100 turns in the secondary,
and 150VAC applied to the primary, the voltage across the secondary is:
75VAC 15. Transformers in which the primary and secondary voltages are
180 degrees out of phase are known as: unlike-wound transformers 16.
Reactive power is always: 90° out of phase with true power
17. If the time for one cycle is 0.1 second, the frequency is: 10Hz
18. If the phase angles of two sine waves are both 0 degrees, then the waves:
are in phase
19. What is the true power in a 2A series RL circuit with a 100© resistor?:
400W 20. The opposing force that an inductor presents to the flow of
alternating current is called: inductive reactance
21. The power factor can be defined as the ratio of true power to: apparent
power
22. In a circuit that has both capacitance and resistance, the current will lead
the voltage: by some angle between 0° and 90°
1. What is the step-down turns ratio of a transformer with 200 turns in the
primary and 100 turns in the secondary?: 2:1
2. Opening the secondary circuit of a current transformer under load will
cause a dangerous level of: induced high voltage
3. What is the frequency of an AC waveform that completes 20 cycles per half
second?: 40Hz
4. A circuit has a peak voltage of 275V. What is the average voltage value?:
175V
5. Each of three equal capacitors in series has: one-third the applied voltage
6. The formula for inductive reactance is: XL = 2ÀfL
7. What is the current flow in a purely resistive AC circuit if the resistance is
15 ohms and the voltage is 150V?: 10A
8. If the area of the plates of a capacitor is increased, the amount of
capacitance: increases
9. The self-induced voltage across an inductance is produced by a change
in: current with respect to time
10. A 30-microfarad capacitor is in parallel with a 15-microfarad capacitor. The
total capacitance is: 45
11. One type of nonsinusoidal waveform is the: square wave
12. According to the power triangle, the apparent power is: greater than the
true power
13. A device that uses electromagnetic induction to transfer electrical energy
from one circuit to another is a(n): transformer
14. If a transformer has 200 turns in the primary, 100 turns in the secondary,
and 150VAC applied to the primary, the voltage across the secondary is:
75VAC 15. Transformers in which the primary and secondary voltages are
180 degrees out of phase are known as: unlike-wound transformers 16.
Reactive power is always: 90° out of phase with true power
17. If the time for one cycle is 0.1 second, the frequency is: 10Hz
18. If the phase angles of two sine waves are both 0 degrees, then the waves:
are in phase
19. What is the true power in a 2A series RL circuit with a 100© resistor?:
400W 20. The opposing force that an inductor presents to the flow of
alternating current is called: inductive reactance
21. The power factor can be defined as the ratio of true power to: apparent
power
22. In a circuit that has both capacitance and resistance, the current will lead
the voltage: by some angle between 0° and 90°
