Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : For measuring the potential difference across a resistance of 600 Ω , the voltmeter with resistance 1000 Ω will be preferred over voltmeter with resistance 4000 Ω . Reason R : Voltmeter with higher resistance will draw smaller current than voltmeter with lower resistance. In the light of the above statements, choose the most appropriate answer from the options given below

A is not correct but R is correct

Both A and R are correct and R is the correct explanation of A

Both A and R are correct but R is not the correct explanation of A

A is correct but R is not correct

EASY

JEE Main

IMPORTANT

Earn 100

A wire $A$ , bent in the shape of an arc of a circle, carrying a current of $2 A$ and having radius $2 cm$ and another wire $B$ , also bent in the shape of an arc of a circle, carrying a current of $3 A$ and having radius of $4 cm$ , are placed as shown in the figure. The ratio of the magnetic fields due to the wires $A$ and $B$ at the common centre $O$ is:

50% studentsanswered this correctly

Important Questions on Magnetic Effects of Current and Magnetism

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 4 September 2020 Shift 2>Q 47

A circular coil has moment of inertia

0.8 kg m^{2}

around any diameter and is carrying current to produce a magnetic moment of

20 A m^{2}

. The coil is kept initially in a vertical position and it can rotate freely around a horizontal diameter. When a uniform magnetic field of

4 T

is applied along the vertical, it starts rotating around its horizontal diameter. The angular speed the coil acquires after rotating by

60^{o}

will be :

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 4 September 2020 Shift 2>Q 48

A paramagnetic sample shows a net magnetisation of

6 A m^{- 1}

when it is placed in an external magnetic field of

0.4 T

at a temperature of

4 K

. When the sample is placed in an external magnetic field of

0.3 T

at a temperature of

24 K

, then the magnetisation will be :

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 5 September 2020 Shift 1>Q 49

A galvanometer of resistance

G

is converted into a voltameter of range

0 - 1 V

by connecting a resistance

R

in series with it. The additional resistance that should be connected in series with

R_{1}

to increase the range of the voltmeter to

0 - 2 V

will be :

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 5 September 2020 Shift 1>Q 50

A square loop of side

2 a,

and carrying current

I

is kept in

X Z

plane with its centre at origin. A long wire carrying the same current

I

is placed parallel to the

z

-axis and passing through the point

(0, b, 0), (b > > a)

. The magnitude of the torque on the loop about

z

-axis is given by.

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 5 September 2020 Shift 1>Q 51

An electrical power line, having a total resistance of

2 Ω,

delivers

1 kW

220 V

. The efficiency of the transmission line is approximately :

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 5 September 2020 Shift 2>Q 52

A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of

6 m A

it produces a deflection of

2 °

, its figure of merit is close to :

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 5 September 2020 Shift 2>Q 53

An iron rod of volume

10^{- 3} m^{3}

and relative permeability

1000

is placed as core in a solenoid with

10 turns {cm}^{- 1}

. If a current of

0.5 A

is passed through the solenoid, then the magnetic moment of the rod will be :

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 15 - Magnetic Effects of Current and Magnetism>JEE Main - 6 September 2020 Shift 1>Q 54

A particle of charge

q

and mass

m

is moving with a velocity

- v \hat{i} (v \neq 0)

towards a large screen placed in the

Y - Z

plane at distance d. If there is magnetic field

\vec{B} = B_{0} \hat{k},

the minimum value of

v

for which the particle will not hit the screen is :

Important Questions on Magnetic Effects of Current and Magnetism

Learn and Prepare for any exam you want !