Electrical level 2 module 1 alternating
current
A 30-microfarad capacitor is in parallel with a 15-microfarad capacitor. The total capacitance is - Correct Answer 45
A circuit has a peak voltage of 275V. What is the average voltage value? - Correct Answer 175V
A device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a(n) - Correct
Answer transformer
According to the power triangle, the apparent power is - Correct Answer greater than the true power
Each of three equal capacitors in series has - Correct Answer one-third the applied voltage
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 - Correct Answer 75VAC
If the area of the plates of a capacitor is increased, the amount of capacitance - Correct Answer increases
If the phase angles of two sine waves are both 0 degrees, then the waves - Correct Answer are in phase
If the time for one cycle is 0.1 second, the frequency is - Correct Answer 10Hz
If the vector diagram of two AC waveforms is a right angle, then the waves - Correct Answer are 90° out of phase
In a circuit that has both capacitance and resistance, the current will lead the voltage - Correct Answer by some angle
between 0° and 90°
In an inductive AC circuit, when the applied voltage is at its maximum negative value, the current is - Correct Answer
zero
One type of nonsinusoidal waveform is the - Correct Answer square wave
Opening the secondary circuit of a current transformer under load will cause a dangerous level of - Correct Answer
induced high voltage
Reactive power is always - Correct Answer 90° out of phase with true power
The formula for inductive reactance is - Correct Answer XL = 2πfL
The opposing force that an inductor presents to the flow of alternating current is called - Correct Answer inductive
reactance
The power factor can be defined as the ratio of true power to - Correct Answer apparent power
The product of the source voltage and the total current is - Correct Answer apparent power
The self-induced voltage across an inductance is produced by a change in - Correct Answer current with respect to
time
Transformers in which the primary and secondary voltages are 180 degrees out of phase are known as - Correct
Answer unlike-wound transformers
What is the current flow in a purely resistive AC circuit if the resistance is 15 ohms and the voltage is 150V? - Correct
Answer 10A
What is the frequency of an AC waveform that completes 20 cycles per half second? - Correct Answer 40Hz
current
A 30-microfarad capacitor is in parallel with a 15-microfarad capacitor. The total capacitance is - Correct Answer 45
A circuit has a peak voltage of 275V. What is the average voltage value? - Correct Answer 175V
A device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a(n) - Correct
Answer transformer
According to the power triangle, the apparent power is - Correct Answer greater than the true power
Each of three equal capacitors in series has - Correct Answer one-third the applied voltage
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 - Correct Answer 75VAC
If the area of the plates of a capacitor is increased, the amount of capacitance - Correct Answer increases
If the phase angles of two sine waves are both 0 degrees, then the waves - Correct Answer are in phase
If the time for one cycle is 0.1 second, the frequency is - Correct Answer 10Hz
If the vector diagram of two AC waveforms is a right angle, then the waves - Correct Answer are 90° out of phase
In a circuit that has both capacitance and resistance, the current will lead the voltage - Correct Answer by some angle
between 0° and 90°
In an inductive AC circuit, when the applied voltage is at its maximum negative value, the current is - Correct Answer
zero
One type of nonsinusoidal waveform is the - Correct Answer square wave
Opening the secondary circuit of a current transformer under load will cause a dangerous level of - Correct Answer
induced high voltage
Reactive power is always - Correct Answer 90° out of phase with true power
The formula for inductive reactance is - Correct Answer XL = 2πfL
The opposing force that an inductor presents to the flow of alternating current is called - Correct Answer inductive
reactance
The power factor can be defined as the ratio of true power to - Correct Answer apparent power
The product of the source voltage and the total current is - Correct Answer apparent power
The self-induced voltage across an inductance is produced by a change in - Correct Answer current with respect to
time
Transformers in which the primary and secondary voltages are 180 degrees out of phase are known as - Correct
Answer unlike-wound transformers
What is the current flow in a purely resistive AC circuit if the resistance is 15 ohms and the voltage is 150V? - Correct
Answer 10A
What is the frequency of an AC waveform that completes 20 cycles per half second? - Correct Answer 40Hz
