A circuit connected to an ac source of emf e = e 0 sin ⁡ 100 t with t in seconds, gives a phase difference of π 4 between the emf e and current i . Which of the following circuits will exhibit this?

R C circuit with R = 1 k Ω and C = 10 μ F

R C circuit with R = 1 k Ω and C = 1 μ F

R L circuit with R = 1 k Ω and L = 1 m H

R L circuit with R = 1 k Ω and L = 10 m H

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A very long solenoid of radius $R$ is carrying current $I (t) = k t e^{- α t} (k > 0),$ as a function of time $(t \geq 0) .$ Counterclockwise current is taken to be positive. A circular conducting coil of radius $2 R$ is placed in the equitorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by:

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Important Questions on Electromagnetic Induction and Alternating Currents

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JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 9th January 2019 Shift 1>Q 77

A conducting circular loop made of a thin wire has area

3.5 \times 10^{- 2} m^{2}

and resistance

10 Ω

It is placed perpendicular to a time-dependent magnetic field

B (t) = (0.4 T) \sin (50 π t)

. The field is uniform in space. Then the net charge flowing through the loop during

t = 0 s

and

t = 10 ms

is close to:

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 9th January 2019 Shift 2>Q 78

A power transmission line feeds input power at

2300 V

to a step down transformer with its primary windings having

4000

turns. The output power is delivered at

230 V

by the transformer. If the current in the primary of the transformer is

5 A

and its efficiency is

90 %

, the output current would be:

HARD

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 9th January 2019 Shift 2>Q 79

A series

A C

circuit containing an inductor

(20 mH),

a capacitor

(120 μ F)

and a resistor

(60 Ω)

is driven by an

A C

source of

24 V / 50 Hz .

The energy dissipated in the circuit in

60 s

is:

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 8th April 2019 Shift 1>Q 81

An alternating voltage

V (t) = 220 \sin (100 π t)

volt is applied to a purely resistive load of

50 Ω

. The time taken for the current to rise from half of the peak value to the peak value is:

HARD

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 8th April 2019 Shift 1>Q 82

A thin strip $10 c m$ long is on a $U$ shaped wire of negligible resistance and it is connected to a spring of spring constant $0.5 N m^{- 1}$ (see figure). The assembly is kept in a uniform magnetic field of $0.1 T .$ If the strip is pulled from its equilibrium position and released, the number of oscillations it performs before its amplitude decreases by a factor of $e$ is $N$ . If the mass of the strip is $50$ grams, its resistance $10 Ω$ and air drag negligible, $N$ will be close to:
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MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 8th April 2019 Shift 2>Q 83

A circuit connected to an ac source of emf

e = e_{0} \sin (100 t)

with

t

in seconds, gives a phase difference of

\frac{π}{4}

between the emf

e

and current

i

. Which of the following circuits will exhibit this?

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 10th April 2019 Shift 1>Q 84

A transformer consisting of

300

turns in the primary and

150

turns in the secondary gives output power of

2.2 k W

. If the current in the secondary coil is

10 A

, then the input voltage and current in the primary coil are:

HARD

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 16 - Electromagnetic Induction and Alternating Currents>JEE Main - 10th April 2019 Shift 2>Q 85

A coil of self inductance

10 m H

and resistance of

0.1 Ω

is connected through a switch to a battery of internal resistance

0.9 Ω

. After the switch is closed, the time taken for the current to attain

80 %

of the saturation value is:

[\ln 5 = 1.6]

Important Questions on Electromagnetic Induction and Alternating Currents

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