# Amperes Law MCQs

NEET  Physics is the scoring paper in the medical entrance examination. Here, you will discover the NEET Physics MCQ Questions for all Concepts as per the latest syllabus. Practice more on a regular basis with these NEET Physics objective questions on air pollution and improve your subject knowledge & problem-solving skills along with time management. NEET Physics Amperes Law Multiple Choice Questions make you feel confident in answering the question in the exam & increases your scores to high.

## MCQ on Amperes Law

1. If a coil carrying current is placed in a uniform magnetic field, then
(a) emf is produced
(b) Torque is produced
(c) Force is produced
(d) Torque and force is produced

2. A coil of diameter 0.2 cm is formed by a 6.28 m long wire and a current of 1 amp is passed in it. The magnetic induction at its centre will be
(a) 6.28 x 10-5 T
(b) 7.25 x 10-5 T
(c) 6.28 x 10-2 T
(d) 6.28 T

Answer: (a) 6.28 x 10-5 T

3. A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be
(a) 2Bn2
(b) n2B
(c) n3B
(d) nB

4. A long straight wire of radius a carries a steady current I. The current is uniformly distributed over its cross-section. The ratio of the magnetic fields B and B’, at radial distances a/2 and 2a respectively from the axis of the wire is:
(a) ¼
(b) ½
(c) 1
(d) 4

5. Compute the magnetic field of a long straight wire that has a circular loop with a radius of 0.05 m. 2 amp is the reading of the current flowing through this closed loop.
(a) 8 x 10-6 T
(b) 8 T
(c) 8 x 10-7 T
(d) 7 x 10-7 T

Answer: (a) 8 x 10-6 T

6. A wire of length L carrying current I is bent into a circle of one turn. The field at the centre of the coil is B1. A similar wire of length L carrying current I is bent into a square of one turn. The field at its centre is B2. Then
(a) B1=B2
(b) B1＞B2
(c) B2＞B1
(d) B1/B2 =2

7. Two long straight parallel wires carry currents I1 and I2, respectively, in the same direction (as shown). The distance between the wires is R. The magnetic field at the centre of the two wires will
(a) μ0(I1-I2)/πR into the plane of the paper (if I1＞I2)
(b) μ0(I2-I1)/πR out the plane of the paper (if I2＞I1)
(c) μ0(I1-I2)/πR2 out the plane of the paper (if I2＞I1)
(d) μ0(I2-I1)/πR2, into the plane of the paper (if I1＞I2)

Answer: (a) μ0(I1-I2)/πR into the plane of the paper (if I1＞I2)

8. Two parallel long wires carry currents iand i2 with i1 ＞i2. When the current is in the same direction, the magnetic field at a point midway between the wire is 20μT If the direction of i1 is reversed the field becomes 30μT. The ratio of i1/i2 is
(a) 4
(b) 3
(c) 2
(d) 1

9. A large metal sheet carries an electric current along its surface. Current per unit length is λ. Magnetic field near the metal sheet is
(a) (½)μ0λ
(b) μ0λ/2π
(c) Μ0λ
(d) μ0/λ2π