NEET Physics Force Magnetic Moment and Torque on Current Carrying Conductor MCQs Set 01

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: A

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: A

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: A

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: A

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: A

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: A

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: A

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: A

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: A

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: A

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: A