Learn electronics engineering concepts, semiconductors, digital electronics, communication systems, and objective questions.
21. The phosphors for which of the following pair are 180° out of phase for VL, VC and VR? A. VC and VR B. VL and VR C. VC and VL D. None of the above Answer Option : C 22. The period of a sine wave is _________ seconds. Its frequency is A. 20 […]
31. The safest value of current the human body can carry for more than 3 second is A. 4 mA B. 9 mA C. 15 mA D. 25 mA Answer Option : B 32. The purpose of a parallel circuit resonance is to magnify A. Current B. Voltage C. Power D. Frequency Answer Option :
41. The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of A. Iron loss in core B. Skin effect C. Increase in temperature D. Capacitive effect between adjacent coil turns Answer Option : A 42. Skin effect occurs when a conductor carries current at _________
51. The series and parallel resonance on L-C circuit’ differs in that A. Series resistance needs a low-resistance source for sharp rise in current B. Series resonance needs a high-resistance source for sharp increase in current C. Parallel resonance needs a low-resistance source for a sharp increase in impedance D. Parallel resonance needs a low-resistance
61. The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is A. 4 kVAR B. 6 kVAR C. 8 kVAR D. 16 kVAR Answer Option : B 62. In a sine wave the slope is constant A. Between 0° and 90°
71. For the same peak value, which of the following wave has the least mean value? A. Half wave rectified sine wave B. Triangular wave C. Sine wave D. Square wave Answer Option : A 72. The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition
81. In a series L-C circuit at the resonant frequency the A. Current is maximum B. Current is minimum C. Impedance is maximum D. Voltage across C is minimum Answer Option : A 82. A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to A. The
81. In a series L-C circuit at the resonant frequency the A. Current is maximum B. Current is minimum C. Impedance is maximum D. Voltage across C is minimum Answer Option : A 82. A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to A. The
