Level 2 Module 1 Alternating Currents
What is The hertz rating of an AC circuit If the frequency is 20 cycles per 1/2
seconds ? F= c/t - ANSWER 40 Hz
Given: A circuit has an RMS voltage of 120V AC. What is the peak to peak voltage?
Rms=.707 x peak - ANSWER 340V
What is the step down turns ratio of a transformer with 200 turns in the primary and
100 turns in the secondary? - ANSWER 2:1
Opening the secondary of a CT under load will cause a dangerous level of ? -
ANSWER Induce high voltage
A circuit has a peak voltage of 275 volts, the average voltage is ? Average = .637 x
peak - ANSWER 175V
Each of three equal capacitors in series has - ANSWER One-third the applied
voltage
The formula for inductive reactance is ? - ANSWER Xl = 2pieFL
The current in an inductive circuit - ANSWER Lags the voltage
Given: an AC Circuit containing resistance only. What is the current flow if the
resistance is 15 ohms and the voltage is 150V? V=IR - ANSWER 10A
When frequency decreases, capacitive reactance - ANSWER Increases
Which of the following is true of the current in a capacitive circuit? - ANSWER It
leads the voltage
In sine wave terminology, the average value is - ANSWER 0.637 x Peak value
All DC rules and laws including ohm's law apply in AC circuits containing only ? -
ANSWER Pure resistance
If the area of the plates of a capacitor is increased, the amount of capacitance -
ANSWER Increases
The self induced voltage across an inductance is equal to the change in - ANSWER
Current with respect to time
Given: A 30 microfarad capacitor in parallel with 15-microfarad capacitor. The total
capacitance is - ANSWER 45
Which of the following opposes any change in circuit current? - ANSWER
Inductance
What is The hertz rating of an AC circuit If the frequency is 20 cycles per 1/2
seconds ? F= c/t - ANSWER 40 Hz
Given: A circuit has an RMS voltage of 120V AC. What is the peak to peak voltage?
Rms=.707 x peak - ANSWER 340V
What is the step down turns ratio of a transformer with 200 turns in the primary and
100 turns in the secondary? - ANSWER 2:1
Opening the secondary of a CT under load will cause a dangerous level of ? -
ANSWER Induce high voltage
A circuit has a peak voltage of 275 volts, the average voltage is ? Average = .637 x
peak - ANSWER 175V
Each of three equal capacitors in series has - ANSWER One-third the applied
voltage
The formula for inductive reactance is ? - ANSWER Xl = 2pieFL
The current in an inductive circuit - ANSWER Lags the voltage
Given: an AC Circuit containing resistance only. What is the current flow if the
resistance is 15 ohms and the voltage is 150V? V=IR - ANSWER 10A
When frequency decreases, capacitive reactance - ANSWER Increases
Which of the following is true of the current in a capacitive circuit? - ANSWER It
leads the voltage
In sine wave terminology, the average value is - ANSWER 0.637 x Peak value
All DC rules and laws including ohm's law apply in AC circuits containing only ? -
ANSWER Pure resistance
If the area of the plates of a capacitor is increased, the amount of capacitance -
ANSWER Increases
The self induced voltage across an inductance is equal to the change in - ANSWER
Current with respect to time
Given: A 30 microfarad capacitor in parallel with 15-microfarad capacitor. The total
capacitance is - ANSWER 45
Which of the following opposes any change in circuit current? - ANSWER
Inductance
