1. A sinusoidal ac voltage which undergoes 100 reversals of polarity per second has a frequency of _______ Hz.
(A) 100
(B) 60
(C) 70
(D) 50
2. The polarity of an ac waveform reverses every _______ cycle.
(A) One
(B) Three
(C) Half
(D) Three
3. The time period of a sine wave of 1 KHz is _______ millisecond.
(A) Both a and b
(B) Two
(C) One
(D) None of above
4. Complex waveforms can be formed by adding _______ to the fundamental frequency.
(A) Sine wave
(B) RMS
(C) Harmonics
(D) Saw tooth
5. A frequency of 1 KHz falls in the _______ frequency range.
(A) Radio
(B) Spectrum
(C) Ultra high
(D) Audio
6. The RMS value of a sinusoidal ac current is equal to its value at an angle of _______ degrees.
(A) 60
(B) 45
(C) 30
(D) 90
7. A sinusoidal current has an RMS value of 7.07A. Its P-P value is ___ Amperes.
(A) 20
(B) 14.14
(C) 28.28
(D) 57.56
8. The actual shape of a complex wave form is determined by _______.
(A) Number of harmonics
(B) All of the above
(C) Amplitude of harmonics
(D) Kind of harmonics
9. In a series RL circuit, voltage _______ the current.
(A) Dissipate
(B) Lags
(C) Store
(D) Leads
10. Skin effect increases the resistance of a conductor at ____ frequencies.
(A) Low
(B) Wider
(C) High
(D) Short
11. A pure inductor or capacitor dissipates _______ power.
(A) Low
(B) High
(C) Moderate
(D) No
12. In a series RLC circuit, phase difference of voltage drops across R and C is _______ degree.
(A) 30
(B) 60
(C) 180
(D) 120
13. For a sine wave RMS value = _______
(A) Both a & b
(B) 1/2 × maximum value
(C) 0.707 × max value
(D) None of above
14. Form factor = _______
(A) Sine value / average value
(B) Average value / volts
(C) RMS value / average value
(D) Average value / RMS value
15. The difference between AC and DC is:
(A) AC changes value DC does not
(B) AC changes direction DC does not
(C) Both a and b
(D) Neither a nor b
16. During each cycle, a sine wave reaches its peak value _______.
(A) Two time
(B) One time
(C) Three time
(D) Depending on the frequency
17. A sine wave of 12 KHz is changing faster than a sine wave of _______.
(A) 10,000 Hz
(B) 15,000 Hz
(C) 20 KHz
(D) 1.25 MHz
18. A sine wave with a period of 2 ms is changing faster than a sine wave having a period of:
(A) 0.0025 ms
(B) 1 ms
(C) 1.5 ms
(D) 1200 ms
19. When a sine wave has a frequency of 60Hz, in 10 seconds it goes through:
(A) 6 cycles
(B) 10 cycles
(C) 1/16 cycles
(D) 600 cycles
20. If the peak value of a sine wave is 10v, the P-P value is
(A) 20V
(B) 5V
(C) 100
(D) None of these