OBJECTIVE QUESTIONS FOR NEET AIIMS JIPMER www wisedane
OBJECTIVE QUESTIONS FOR NEET AIIMS JIPMER www. wisedane. com
PHYSICS Alternating Current MCQ’S SET 2 www. wisedane. com
Q 1. Current in a circuit is wattles, if A. Current is alternating B. Resistance in circuit is zero C. Inductance in circuit is zero D. Resistance and inductance both are zero www. wisedane. com
ANSWER (B) EXPLANATION Ø Power in a circuit is consumed only on account of resistance which must be zero for wattles current www. wisedane. com
Q 2. Energy needed to establish an alternating current I in coil of self inductance L is www. wisedane. com
ANSWER (D) EXPLANATION www. wisedane. com
Q 3. The power factor of a series LCR circuit when at resonance is A. Zero B. 0. 5 C. 1. 0 D. Depends on value of L, C, R www. wisedane. com
ANSWER (C) EXPLANATION www. wisedane. com
Q 4. In an a. c. circuit, V and I are given by V = 100 sin (100 t) volt I = 100 sin (100 t ) m. A The power dissipated in the circuit is A. 104 watt B. 10 watt C. 2. 5 watt D. 5 watt www. wisedane. com
ANSWER (D) EXPLANATION www. wisedane. com
Q 5. Power delivered by the source in the circuit is maximum, when www. wisedane. com
ANSWER (B) EXPLANATION www. wisedane. com
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ANSWER (A) EXPLANATION www. wisedane. com
Q 7. A lamp in which 10 amp current can flow at 15 V, is connected with an alternating source of potential 220 V. The frequency of source is 50 Hz. The inductance of choke coil require to light the bulb is A. 0. 07 H B. 0. 14 H C. 0. 28 H D. 1. 07 H www. wisedane. com
ANSWER (A) EXPLANATION www. wisedane. com
Q 8. A coil has L = 0. 04 H and R = 12 ohm. When it is connected to 220 V, 50 Hz supply, the current flowing through the coil is A. 10. 7 A B. 11. 7 A C. 14. 7 A D. 12. 7 A www. wisedane. com
ANSWER (D) EXPLANATION www. wisedane. com
Q 9. For the series LCR circuit shown in Figure. What is the resonance frequency and the amplitude of the current at the resonating frequency ? www. wisedane. com
ANSWER (A) EXPLANATION www. wisedane. com
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ANSWER (A) EXPLANATION www. wisedane. com
Q 11. In an A. C. circuit, voltage applied is V = 220 sin 100 t. if the impedance is 110 Ω and phase difference between current and voltage Is 60 O, The power consumption is equal to A. 55 W B. 110 W C. 220 W D. 330 W www. wisedane. com
ANSWER (B) EXPLANATION www. wisedane. com
Q 12. It is desired to send an alternating current 5 sin 400 t through a solenoid that has a self-inductance of 3 m. H. If the resistance of the solenoid is assumed to be negligible, the voltage impressed across the solenoid terminals to provide this current is A. 5 cos 400 t B. 2000 cos 400 t C. 6 cos 400 t D. 6 sin 400 t www. wisedane. com
ANSWER (C) EXPLANATION www. wisedane. com
Q 13. A 60 volt -10 watt bulb is operated at 100 volt -60 Hz a. c. The inductance required is A. 2. 45 H B. 0. 32 H C. 0. 64 H D. 1. 28 H www. wisedane. com
ANSWER (D) EXPLANATION www. wisedane. com
A. 9. 25 A B. 0. 5 A C. 0. 75 A D. 1. 0 A www. wisedane. com
ANSWER (B) EXPLANATION www. wisedane. com
Q 15. In figure shown final value of current in 10 Ω resistor, when plug of key K is inserted is A. 3/10 A B. 3/20 A C. 3/11 A D. Zero www. wisedane. com
ANSWER (D) EXPLANATION Ø As resistance of 1 H coil is zero, the entire current flows through the coil. Ø Current through 10 Ω resistance is zero. www. wisedane. com
Q 16. A series combination of R, L, C is connected to an a. c. source. If the resistance is 3 Ω and the reactance is 4 Ω, the power factor of the circuit is : A. 0. 4 B. 0. 6 C. 0. 8 D. 1. 0 www. wisedane. com
ANSWER (B) EXPLANATION www. wisedane. com
Q 17. In the circuit shown in Figure. What will be the reading of the voltmeter ? A. 300 V B. 900 V C. 200 V D. 400 V www. wisedane. com
ANSWER (C) EXPLANATION www. wisedane. com
Q 18. An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3 Ω, the phase difference between the applied voltage and the current in the circuit is www. wisedane. com
ANSWER (B) EXPLANATION www. wisedane. com
Q 19. An inductor L and a capacitor C are connected in the circuit as shown in Figure. The frequency of power supply is equal to the resonance frequency of the circuit. Which ammeter will read zero ampere ? A. A 1 B. A 2 C. A 3 D. None of these www. wisedane. com
ANSWER (C) EXPLANATION Ø Here, L and C are in parallel. When frequency of power supply is equal to the resonant frequency of the circuit, resonance occurs. Ø In the parallel resonance circuit, current becomes zero. Therefore, ammeter A 3 reads zero ampere. www. wisedane. com
Q 20. In the circuit shown in figure voltmeter reads 100 V. Then L is A. 0. 1 H B. 0. 2 H C. 0. 02 H D. 0. 01 H www. wisedane. com
ANSWER (D) EXPLANATION Ø As e. m. f. of source is 100 V, therefore, voltmeter can read 100 V only at resonance. As www. wisedane. com
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