1. A current is said to be alternating when it changes in ? magnitude only direction only both magnitude and direction none Answer: both magnitude and direction Explanation: View Answer Discuss in Forum Report Question

 2. If two sinusoidal of the same frequency but of different amplitudes and phase difference are added, the resultant is a ? sinusoid of double the original frequency sinusoid of the same frequency non-sinusoid sinusoid of half the original frequency Answer: sinusoid of the same frequency Explanation: View Answer Discuss in Forum Report Question

 3. The reactance offered by a capacitor to ac of frequency 50 Hz is 102. If the frequency is increased to 100 Hz, reactance becomes ? 20? 40? 5? 2.5? Answer: 5? Explanation: View Answer Discuss in Forum Report Question

 4. A square wave is fed to an R-C circuit. Then ? voltage across both R and C is square voltage across R is square and across C is not square voltage across both R and C is not square voltage across C is square and across R is not square Answer: voltage across both R and C is not square Explanation: View Answer Discuss in Forum Report Question

 5. A 240 V single-phase ac source is connected to a load with an impedance of 10 2. A capacitor is connected in parallel with the load. If the capacitor supplies 1,250 VAR, the real power supplied by the source is ? 3,600 W 2,400 W 2,880 W 1,200 W Answer: 2,880 W Explanation: View Answer Discuss in Forum Report Question

 6. A source of angular frequency 1 rad/sec has a source impedance consisting of 1 resistance in series with 1 H inductance. The load that will obtain the maximum power transfer is ? 12 resistance in series with 1 F capacitor 1? resistance 1? resistance in parallel with 1 H inductance 12 resistance in parallel with 1 F capacitor Answer: 12 resistance in series with 1 F capacitor Explanation: View Answer Discuss in Forum Report Question

 7. The rated voltage of a 3-phase power system is given as ? rms phase voltage rms line-to-line voltage peak line-to-line voltage peak phase voltage Answer: rms line-to-line voltage Explanation: View Answer Discuss in Forum Report Question

 8. For a 3-phase load balanced condition, each phase has the same value of ? impedance resistance power factor all of these Answer: all of these Explanation: View Answer Discuss in Forum Report Question

 9. A 3-phase delta-connected symmetrical load consumes P watts of power from a balanced supply. If the same load is connected in star to the same supply, then what is the power consumption ? P P/3 3P ?3P Answer: P/3 Explanation: View Answer Discuss in Forum Report Question

 10. Two resistors of equal values are connected series across the lines B and C of a symmetrical 3-phase, 400 V system. What is the magnitude of the voltage between the line A and the junction of resistors ? 400//3 100/3 200/3 400/3 Answer: 200/3 Explanation: View Answer Discuss in Forum Report Question
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