EASY
12th West Bengal Board
IMPORTANT
Earn 100

Range of a milli-ammeter is 0.15 mA. The resistance of the ammeter is 5 Ω. What is required to be done to change the metal to a voltmeter to read upto 0.75 volt?

Important Questions on Electromagnetism

EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 20
The coil of moving-coil galvanometer has area 3 cm2, number of turns 20 and it rotates in a radial magnetic field of magnitude 0.1 T. If the galvanometer shows a deflection of 4° for a current of 10 mA through it, then what is the restoring torque per unit twist of the suspension fibre?
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 21
A 10 cm long solenoid has number of turns 200 cm-1. A current of 0.1 A flows through each turn. Find the magnetic moment of its equivalent bar magnet. Given the diameter of the solenoid is 10 cm. Determine the magnetic field on its axis at a point 2 m away from the mid-point of its length.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 22
A tangent galvanometer is so designed that 5,50 or 500 turns can be used. A current of 0.5 A sent through 50 turns produces a deflection of 45°. Find the deflection produced when the same current passes through 5 turns, 
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 22
A tangent galvanometer is so designed that 5,50 or 500 turns can be used. A current of 0.5 A sent through 50 turns produces a deflection of 45°. Find the deflection produced when the same current passes through 500 turns
MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 23
A tangent galvanometer and a silver voltmeter are connected in series and a current is passed through them for 15 minutes maintaining the deflection of galvanometer at 45° all through. If the amount of silver deposited on the cathode of the voltmeter during this period of time be 0.336 gm, what is the value of the reduction factor of the galvanometer? [ECE of silver =0.00113gm/C]
MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 24
A tangent galvanometer shows a deflection of 45° when 10 mA of current is passed through it. If the horizontal component of the earth's magnetic field is BH=3.6×10−5 T and radius of the coil is 10 cm, find the number of turns in the coil.
MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 25
A circular coil of 100 turns and having an effective radius of 0.05 m carries a current of 0.1 A. How much work is required to turn it in an external magnetic field of 1.5 Wb m-2 through 180° about an axis perpendicular to the magnetic field. The plane of the coil is initially perpendicular to the magnetic field
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 8 - Electromagnetism>EXERCISE 8>Q 26
A circular coil of 20 turns and 10 cm radius is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, find  total torque on the coil,