NEET Physics Biot Savarts Law and Amperes Circuital Law MCQs Set A

a)

b)

c) it obeys inverse cube law

d) it is along the line joining electron and point of observation

Answer:

Question: Ampere’s circuital law states that

a)

b)

c)

d)

Answer:

Question: The magnetic field around a long straight current carrying wire is

a) unsymmetrical

b) cylindrical symmetry

c) spherical symmetry

d) cubical symmetry

Answer: unsymmetrical

Question: If a copper rod carries a direct current, the magnetic field associated with the current will be

a) both inside and outside the rod

b) neither inside nor outside the rod

c) only outside the rod

d) only inside the rod

Answer: both inside and outside the rod

Question:

a)

b)

c)

d)

Answer:

Question: The magnetic field B at a point on one end of a solenoid having n turns per metre length and carrying a current of i ampere is given by

a)

b)

c)

d)

Answer:

Question: A helium nucleus makes a full rotation in a circle of radius 0.8 meter in 2 sec. The value of the magnetic field induction B in tesla at the centre of circle will be

a)

b)

c)

d)

Answer:

Question: Which one of the following is the correct expression for magnetic field on the axis of a circular current loop with xaxis as its axis?

a)

b)

c)

d)

Answer:

Question: If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be

a) only outside the pipe

b) neither inside nor outside the pipe

c) both inside and outside the pipe

d) only inside the pipe

Answer: only outside the pipe

Question: Energy in a current carrying coil is stored in the form of

a) magnetic field

b) heat

c) electric field

d) dielectric strength

Answer: magnetic field

Question:

a)

b)

c)

d)

Answer:

Question:

a) zero

b) 8 nli

c) None of these

d) 4 ni

Answer: zero

Question:  Which of the following statements is/are correct?
I. The magnetic field in the open space inside the toroid is constant.
II. The magnetic field in the open space exterior to the toroid is constant.
III. The magnetic field inside the core of toroid is constant.

a) I only

b) II and III

c) I and II

d) III only

Answer: I only

Question:

a)

b)

c)

d)

Answer:

Question:

a) 5.0 × 10^–8 T

b) 7.5 × 10^–8 T

c) 5.5 × 10^–8 T

d) 4.5 × 10^–8 T

Answer: 5.0 × 10^–8 T

Question:

a) Assertion is incorrect, reason is correct

b) Assertion is correct, reason is incorrect

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: Assertion is incorrect, reason is correct

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

Question: Assertion : If the current in a solenoid is reversed in direction while keeping the same magnitude, the magnetic field energy stored in the solenoid decreases.
Reason : Magnetic field energy density is proportional to square of current.

a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

c) Assertion is correct, reason is incorrect

d) Assertion is incorrect, reason is correct

Answer: Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Question: A current I flows along the length of an infinitely long, straight, thin walled pipe. Then

a) the magnetic field at any point inside the pipe is zero

b) the magnetic field is different at different points inside the pipe

c) the magnetic field at all points inside the pipe is the same, but not zero

d) the magnetic field is zero only on the axis of the pipe

Answer: the magnetic field at any point inside the pipe is zero

Question:

a)

b)

c)

d)

Answer:

Question: A long straight wire in the horizontal plane carries a current of 75 A in north of south direction, magnitude and direction of field B at a point 3 m east of the wire is

a) 5 × 10^–6 T, vertical up

b) 4 × 10^–6 T, vertical down

c) 5 × 10^–6 T, vertical down

d) 4 × 10^–6 T, vertical up

Answer:  5 × 10^–6 T, vertical up

Question:

a) 5 × 10^–5

b) 7 × 10^–5

c) 12×10^–5

d) 10^–5

Answer: 5 × 10^–5

Question: A circular coil of wire consisting of 100 turns each of radius 9 cm carries a current of 0.4 A. The magnitude of manetic field at the centre of the coil is

a) 2.79 × 10^–4 T

b) 2.4 × 10^–4 T

c) 3.5 × 10^–4 T

d) 3 × 10^–4 T

Answer: 2.79 × 10^–4 T

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a) 8.0 A

b) 4.0 A

c) 2.0 A

d) 1.0 A

Answer: 8.0 A

Question: A solenoid of length 0.6 m has a radius of 2 cm and is made up of 600 turns If it carries a current of 4 A, then the magnitude of the magnetic field inside the solenoid is

a) 5.024 × 10^–3 T

b) 6.024 × 10^–3 T

c) 8.024 × 10^–3 T

d) 7.024 × 10^–3 T

Answer: 5.024 × 10^–3 T

Question: A long solenoid carrying a current produces a magnetic field B along its axis. If the current is double and the number of turns per cm is halved, the new value of the magnetic field is

a) B

b) 2 B

c) B/2

d) 4 B

Answer: B

Question: If we triple the radius of a coil keeping the current through it unchanged, then the magnetic field at any point at a large distance from the centre becomes approximately how much times ?

a) 4

b) 3

c) 8

d) 9

Answer: 4

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a) zero

b)

c)

d)

Answer: zero

Question:

a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

c) Assertion is correct, reason is incorrect

d) Assertion is incorrect, reason is correct.

Answer: Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Question: A current i ampere flows along an infinitely long straight thin walled tube, then the magnetic field at any point inside the tube is

a) zero

b) infinite

c)

d)

Answer:  zero

Question:

a)

b)

c)

d)

Answer:

Question: The magnetic induction at a point P which is at a distance of 4 cm from a long current carrying wire is 10^–3 T. The field of induction at a distance 12 cm from the current will be

a) 3.33 × 10^–4 T

b) 3 × 10^–3 T

c) 1.11 × 10^–4 T

d) 9 × 10^–3 T

Answer: 3.33 × 10^–4 T

Question: Two concentric circular coils of ten turns each are situated in the same plane. Their radii are 20 and 40 cm and they carry respectively 0.2 and 0.4 ampere current in opposite direction. The magnetic field in weber/m² at the centre is

a) zero

b)

c)

d)

Answer: zero

Question:

a)

b)

c)

d)

Answer:

Question: Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency f Hz. The magnitude of magnetic induction at the centre of the ring is

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question: A cell is connected between two points of a uniformly thick circular conductor and i1 and i2 are the currents flowing in two parts of the circular conductor of radius a. The magnetic field at the centre of the loop will be

a) zero

b)

c)

d)

Answer: zero