MCQs of Magnetism and Matter

Magnetism and Matter MCQs

MCQs of Magnetism and Matter

Showing 131 to 140 out of 145 Questions

131.

The unit of

\frac{1}{\sqrt{μ_{0} ε_{0}}}

is same as the unit of _____ .

(a)	acceleration
(b)	force
(c)	velocity
(d)	displacement

132.

A magnet is oscillating in a horizontal plane. Its periodic time is 8 s. If it is cut along its length in two pieces and one piece is oscillating in horizontal plane. The periodic time of the piece is _____ .

(a)	4 s
(b)	2 s
(c)	8 s
(d)	16 s

133.

In a solenoid, magnetic intensity is 1000 A m^-1 and intensity of magnetization is 4950 × 10³ m^-1. Find its magnetic susceptibility.

(a)	4950
(b)	4950 × 10³
(c)	2475
(d)	4951

134.

Magnetic susceptibility of a material of a rod is 499. Find absolute permeability of the material of the rod

(a)	$π \times 10^{- 4} \frac{Tm}{A}$
(b)	$4 π \times 10^{- 4} \frac{Tm}{A}$
(c)	$3 π \times 10^{- 4} \frac{Tm}{A}$
(d)	$2 π \times 10^{- 4} \frac{Tm}{A}$

135.

The force between two magnetic poles is F. Now, the pole strength of the each pole is doubled. Now, calculate the new force

(a)	4F
(b)	2F
(c)	$\frac{F}{2}$
(d)	$\frac{F}{4}$

136.

The magnetic susceptibility of a paramagnetic substance at -73°C is 0.0050. Calculate magnetic susceptibility at -173°C.

(a)	0.010
(b)	0.0025
(c)	0.0020
(d)	0.0030

137.

Magnetic dipole moment of a bar magnet is m and length is 10 cm. It is broken in two pieces of lengths 6 cm and 4 cm. They are put at right angle to each other with the opposite poles together. Find the resultant dipole moment of the combination.

(a)	15 m
(b)	$\sqrt{52} m$
(c)	$\frac{\sqrt{52}}{10} m$
(d)	$\sqrt{\frac{52}{5}} m$

138.

A magnetic needle is lying in equilibrium in a uniform magnetic field

\vec{B}

. To rotate its through

60 °

, we need to spend energy W. How much torque needs to be applied to keep it in that position ?

(a)	$\frac{\sqrt{3}}{2} W$
(b)	$\frac{1}{2} W$
(c)	$\sqrt{3} W$
(d)	$W$

139.

There are 2 × 10²⁴ molecular dipoles in a paramagnetic salt. Each has dipole moment 1.5 × 10^-23 A m². Find the maximum magnetization in the specimen.

(a)	30 A m²
(b)	20 A m²
(c)	50 A m²
(d)	200 A m²

140.

A thin magnetic needle oscillates in a horizontal plane with a period T. It is broken into n equal parts. Find the periodic time of each part.

(a)	$T$
(b)	$T n^{2}$
(c)	$\frac{T}{n}$
(d)	$\frac{T}{n^{2}}$

Showing 131 to 140 out of 145 Questions