NEET Physics Force Magnetic Moment and Torque on Current Carrying Conductor MCQs Set A

a)

b)

c)

d)

Answer:

Question:  Two straight long conductors AOB and COD are perpendicular to each other and carry currents I₁ and I₂. The magnitude of the magnetic induction at a point P at a distance a from the point O in a direction perpendicular to the plane ABCD is

a)

b)

c)

d)

Answer:

Question:  The magnetic dipole moment of a current loop is independent of

a) magnetic field in which it is lying

b) number of turns

c) area of the loop

d) current in the loop

Answer:  magnetic field in which it is lying

Question:  If m is magnetic moment and B is the magnetic field, then\ the torque is given by

a)

b)

c)

d)

Answer:

Question:  The magnetic moment of a circular coil carrying current is

a) directly proportional to the square of the length of the wire in the coil

b) inversely proportional to the length of the wire in the coil

c) directly proportional to the length of the wire in the coil

d) inversely proportional to the square of the length of the wire in the coil

Answer:  directly proportional to the square of the length of the wire in the coil

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a) 7/8

b) 9/8

c) 1

d) None of these

Answer:  7/8

Question:

a) along oy

b) along ox

c) opposite to oy

d) opposite to ox

Answer: along oy

Question:  P, Q and R are long straight wires in air, carrying currents as shown. The force on Q is directed

a) to the left

b) to the right

c) along the current in Q

d) None of these

Answer:  to the left

Question:  A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon

a) shape of the loop

b) area ot the loop

c) magnetic field

d) value of the current

Answer:  shape of the loop

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

More Questions..........................................................

Question: Figure shows a spiral coil of negligible mass lying in a plane perpendicular to uniform magnetic field. When the key is closed the spiral coil will

a) expand

b) contract

c) neither contract nor expand

d) tend to rotate about an axis passing through A and B.

Answer:  expand

Question:

a)

b)

c)

d)

Answer:

Question:  A conducting circular loop of radius r carries a constant current i. It is placed in a uniform magnetic field B such that B is perpendicular to the plane of the loop. The magnetic force acting on the loop is

a) zero

b) i r B

c)

d)

Answer:  zero

Question:  Two long wires are hanging freely. They are joined first in parallel and then in series and then are connected with a battery. In both cases which type of force acts between the two wires?

a) Attraction force when in parallel and repulsion force when in series

b) Repulsion force when in parallel and attraction force when in series

c) Attraction force in both cases

d) Repulsion force in both cases

Answer:  Attraction force when in parallel and repulsion force when in series

Question:  A current carrying conductor placed in a magnetic field experiences maximum force when angle between current and magnetic field is

a)

b)

c)

d) zero

Answer:

Question:  A current of 3 A is flowing in a linear conductor having a length of 40 cm. The conductor is placed in a magnetic field of strength 500 gauss and makes an angle of 30º with the direction of the field. It experiences a force of magnitude

a) 3 × 10^–2 N

b) 3 × 10⁴ N

c) 3 × 10^–4 N

d) 3 × 10² N

Answer:  3 × 10^–2 N

Question:  A current of 10 A is flowing in a wire of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform magnetic field of 2 T. The angle between the magnetic field and the direction of the current is

a) 30°

b) 45°

c) 60°

d) 90°

Answer: 30°

Question:  If a current is passed through a spring then the spring will

a) compress

b) expand

c) remains same

d) none of these

Answer:  compress

Question: A circular loop of area 0.02 m2 carrying a current of 10A, is held with its plane perpendicular to a magnetic field induction 0.2 T. The torque acting on the loop is

a) zero

b) 0.01 Nm

c) 0.001 Nm

d) 0.8 Nm

Answer: zero

Question: Through two parallel wires A and B, 10A and 2A of currents are passed respectively in opposite directions. If the wire A is infinitely long and the length of the wire B is 2m, then\ force on the conductor B, which is situated at 10 cm distance from A, will be

a) 8 × 10^–5 N

b) 4 × 10^–5 N

c) 8 × 10^–7 N

d) 4 × 10^–7 N

Answer: 8 × 10^–5 N

Question:  An 8 cm long wire carrying a current of 10 A is placed inside a solenoid perpendicular to its axis. If the magnetic field inside the solenoid is 0.3 T, then magnetic force on the wire is

a) 0.24 N

b) 0.34 N

c) 0.44 N

d) 0.14 N

Answer: 0.24 N

Question:  The orbital speed of electron orbiting around a nucleus in a circular orbit of radius 50 pm is 2.2 × 10⁶ ms^–1. Then the magnetic dipole moment of an electron is

a) 8.8 × 10^–25 Am²

b) 1.6 × 10^–19 Am²

c) 8.8 × 10^–26 Am²

d) None of these

Answer: 8.8 × 10^–25 Am²