MEDIUM
JEE Main
IMPORTANT
Earn 100

The rms current in an AC circuit is 2 A. If the watt-less current is 3 A, then what is the power factor?

50% studentsanswered this correctly

Important Questions on Alternating Current

MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 2
2.5π μF capacitor and 3000 Ω resistance are joined in series to an ac source of 200 V and 50 s-1 frequency. The power factor of the circuit and the power dissipated in it will be, respectively,
MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 3
The self-inductance of a choke coil is 10 mH. When it is connected with a 10 V DC source, then the loss of power is 20 W. When it is connected with 10 V AC source, loss of power is 10 W. The frequency of AC source will be
MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 4
A group of electric lamps having a total power rating of 1000 W is supplied by an ac voltage E=200sin310t+60°. The r.m.s. value of the circuit current is
MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 5
In an LR circuit, the inductive reactance is equal to the resistance R of the circuit. An emf E=E0sinωt is applied to the circuit. The power consumed in the circuit is
HARD
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 6
An LCR series circuit with a resistance of 100 Ω is connected to an ac source of 200 V (r.m.s.) and angular frequency 300 rad s-1. When only the capacitor is removed, the current lags behind the voltage by 60°. When only the inductor is removed, the current leads the voltage by 60°. The average power dissipated is
MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 7

In the circuit shown in figure, neglecting source resistance, the voltmeter and ammeter readings, respectively, will be

Question Image

MEDIUM
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 8

In the circuit shown in the figure, the ac source gives a voltage V=20cos(2000t). Neglecting source resistance, the voltmeter and ammeter readings will be

Question Image

HARD
JEE Main
IMPORTANT
Chapterwise/Topicwise Daily Practice Problems (DPP) Magnetism and Electromagnetic Induction JEE Main & Advanced>Chapter 5 - Alternating Current>DPP>Q 9
An ac source of angular frequency ω is fed across a resistor R and a capacitor C in series. The current registered is I. If now, the frequency of the source is changed to ω3 (but maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency ω.