AC FUNDAMENTAL MCQs 20 min Score: 0 Attempted: 0/20 Subscribe 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
