EASY
12th West Bengal Board
IMPORTANT
Earn 100

A straight wire carries a current of 3 A. Calculate the magnitude of the magnetic field at a point 15 cm away from the wire. 

Important Questions on Electromagnetism

MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 6
Calculate the magnetic field at the centre of coil in the form of square of side 4 a carrying current I. 
MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 7

As shown in Fig. a cell is connected across X and Y of a uniform circular conductor. Prove that the magnetic field at the centre will be zero.

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HARD
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 8
Two circular coils X and Y having radii R and R2 respectively are placed in horizontal plane with their centres coinciding with each other. Coil X has a current I flowing through it in the clockwise sense. What must be the current in coil $Y$ to make the total magnetic field at the common centre of the two coils, zero. With the same current flowing in the two coils if the coil Y is now lifted vertically upwards through a distance R, what would be the net magnetic field at the centre of the coil.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 9
A solenoid of length 1 m has a radius of 1 cm and is made up of 1000 turns. It carries a current of 10 A. What is the magnitude of the magnetic field inside the solenoid?
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 10
An electron of kinetic energy 25 keV moves perpendicular to the direction of a uniform magnetic field of 0.2 mT. Calculate the period of revolution of the electron in the magnetic field.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 11
A square coil of side 10 cm has 20 turns and carries a current of 12 A. The coil is suspended vertically ; the normal to the plane of the coil makes an angle of 30° with the direction of a uniform horizontal magnetic field. If the torque experience by the coil equals 0.96 N m, find the magnitude of the magnetic field. 
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 13
An α -particle and a proton are accelerated from rest through the same potential difference and both enters into a uniform perpendicular magnetic field. Find the ratio of their radii of curvature.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 14
In an exercise to increase current sensitivity of a galvanometer by 25%, its resistance is also increased 1.5 times. How will the voltage sensitivity of the metre be affected?