7 + Interview Questions in PERMANENT MAGNETS IN GENERAL AWARENESS Page 1 InterviewSolution

1.	A uniform magnetic field of 0.20 x 10-3T exists in the space. Find the change in the magnetic scalar potential as one moves through 50cm along the field.
Answer» B = –dV/dl => dv = –B dℓ = – 0.2 × 10^–3 × 0.5 = – 0.1 × 10^–3T-m Since the sigh is –ve therefore potential decreases.

1.

A uniform magnetic field of 0.20 x 10-3T exists in the space. Find the change in the magnetic scalar potential as one moves through 50cm along the field.

Answer»

B = –dV/dl => dv = –B dℓ = – 0.2 × 10^–3 × 0.5 = – 0.1 × 10^–3T-m

Since the sigh is –ve therefore potential decreases.

2.	Let r be the distance of a point on the axis of a bar magnet from its centre. The magnetic field at such a point is proportional to(a) 1/r(b) 1/r2(c) 1/r3(d) none of these.
Answer» (d) none of these.

3.	Two short magnets of equal dipole moments M are fastened perpendicuarly at their centres (figure 36-Q1). The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is
Answer» The correct answer is (c).

4.	A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the axis of the loop is in(a) end-on position (b) broadside-on position(c) both (d) none.
Answer» (a) end-on position

5.	A circular loop carrying a current is replaced by en equivalent magnetic dipole. A point on the loop is in (a) end-on position (b) broadside-on position(c) both (d) none.
Answer» (b) broadside-on position

6.	A horizontal circular loop carries a current that looks clockwise when viewed from above. It is replaced by an equivalent magnetic dipole consisting of a south pole S and a north pole N. (a) The line SN should be along a diameter of the loop. (b) The line SN should be perpendicular to the plane of the loop. (c) The south pole should be below the loop. (d) The north pole should be below the loop.
Answer» (b) The line SN should be perpendicular to the plane of the loop. (d) The north pole should be below the loop.

6.

Answer»

(b) The line SN should be perpendicular to the plane of the loop.

(d) The north pole should be below the loop.

7.	To measure the magnetic moment of a bar magnet, one may use(a) a tangent galvanometer(b) a deflection galvanometer if the earth's horizontal field is known(c) an oscillation magnetometer if the earth's horizontal field is known(d) both deflection and oscillation magnetometer if the earth's horizontal field is not known.
Answer» (b) a deflection galvanometer if the earth's horizontal field is known (c) an oscillation magnetometer if the earth's horizontal field is known (d) both deflection and oscillation magnetometer if the earth's horizontal field is not known.

7.

Answer»

(b) a deflection galvanometer if the earth's horizontal field is known

(c) an oscillation magnetometer if the earth's horizontal field is known

(d) both deflection and oscillation magnetometer if the earth's horizontal field is not known.