MCQs of Magnetism and Matter

Magnetism and Matter MCQs

MCQs of Magnetism and Matter

Showing 91 to 100 out of 145 Questions

91.

When a paramagnetic substance is brought near a north pole or a south pole of a bar magnet, it _____ .

(a)	experiences repulsion
(b)	experiences attraction
(c)	does not experience attraction or repulsion
(d)	experiences attraction or repulsion depending upon while pole is brought near to it.

92.

A true test of magnetism is _____ .

(a)	only attraction
(b)	only repulsion
(c)	both attraction as well as repulsion
(d)	neither attraction nor repulsion

93.

A bar magnet of length l, pole strength 'p' and magnetic moment

\vec{m}

is split

\frac{l}{2}

into two equal pieces each of length. The magnetic moment and pole strength of each piece is respectively _____ and _____ .

(a)	$\vec{m}, \frac{p}{2}$
(b)	$\frac{\vec{m}}{2}, p$
(c)	$\frac{\vec{m}}{2}, \frac{p}{2}$
(d)	$\vec{m}, p$

94.

Magnetization for vaccum is _____.

(a)	negative
(b)	positive
(c)	infinite
(d)	zero

95.

A bar magnet of magnetic moment

\vec{m}

is placed in uniform magnetic field

\vec{B}

such that

\vec{m} ∥ \vec{B}

. In this position, the torque and force acting on it are _____ and _____ respectively.

(a)	0, 0
(b)	$\vec{m} \times \vec{B}, mB$
(c)	$\vec{m} \cdot \vec{B}, mB$
(d)	$\vec{m} \cdot \vec{B}, \vec{m} \times \vec{B}$

96.

A magnetic needle kept non - parallel to the magnetic field in a non - uniform magnetic field experiences ______.

(a)	a force but not a torque
(b)	a torque but not a force
(c)	both a force and a torque
(d)	neither a force nor a torque

97.

A steamer would like to move in the direction making an angle of 10° south with the west. The magnetic declination at that place 17° west from the north. The steamer should move in a direction _____ .

(a)	making an angle of 83° west with the north pole of Earth
(b)	making an angle of 83° east with the north pole of Earth
(c)	making an angle of 27° west with the south pole of Earth
(d)	making an angle of 27° east with the south pole of Earth

98.

A toroid would 100 turns/m of wire carries a current of 3 A. The core of toroid is made of iron having relative magnetic permeability of μ_r = 5000 μ₀ under given conditions. The magnetic field inside the iron is _____. (Take μ₀= 4π × 10^-7 T m A^-1)

(a)	0.15 T
(b)	0.47 T
(c)	1.5 × 10^-2 T
(d)	1.88 T

99.

A magnetic needle placed in uniform magnetic field has magnetic moment 6.7 × 10^-2 Am², and moment of inertia of 15 × 10^-6 kgm². It performs 10 complete oscillations in 6.70 s. What is the magnitude of the magnetic field ?

(a)	0.2 T
(b)	0.02 T
(c)	0.002 T
(d)	0.0002 T

100.

The Earth' s magnetic field at some place on magnetic equator of Earth is 0.4 G . Estimate the magnetic dipole moment of the Earth . Consider the radius of Earth at that place to be 6.4 \times 10^{6} m . (\frac{μ_{0}}{4 π} = 10^{- 7} and 1 G = 10^{- 4} T)

(a)	1.05 × 10²⁰ Am²
(b)	1.05 × 10²¹ Am²
(c)	1.05 × 10²² Am²
(d)	1.05 × 10²³ Am²

Showing 91 to 100 out of 145 Questions