MCQs of Magnetism and Matter

Magnetism and Matter MCQs

MCQs of Magnetism and Matter

Showing 51 to 60 out of 145 Questions

51.

The earth's, magnetic field at some place on magnetic equator of earth is 0.5 × 10^-4 T. Consider the radius of earth at that place as 6400 km. Then, magnetic dipole moment of the earth is _____ Am². (μ0 = 4π × 10^-7 TmA^-1)

(a)	1.05 × 10²³
(b)	1.15 × 10²³
(c)	1.31 × 10²³
(d)	1.62 × 10²³

52.

The effective length of a magnet is 31.4 cm and its pole strength is 0.8 Am. The magnetic moment, if it is bent in the form of a semicircle is _____ Am².

(a)	1.6
(b)	0.16
(c)	1.2
(d)	0.12

53.

At a place on earth, the vertical component of earth's, magnetic field is

\sqrt{3}

time its horizontal component. The angle of dip at this place is _____ .

(a)	$30 °$
(b)	$45 °$
(c)	$60 °$
(d)	$0 °$

54.

Pole strength of a magnet is 5 Am and its magnetic length is 10 cm. Calculate the magnetic dipole moment of it.

(a)	0.5 A m²
(b)	5 A m²
(c)	50 A m²
(d)	20 A m²

55.

Total number of turns, radius and the current passing through the solenoid are 100, 2 cm and 2 mA respectively. Calculate the magnetic dipole moment.

(a)	4π × 10^-5 A m²
(b)	2π × 10^-4 A m²
(c)	4π × 10^-4 A m²
(d)	8π × 10^-5 A m²

56.

Velocity of an electron moving round the centre of an atom is v. Find its orbital magnetic moment.

(a) $\frac{1}{2} {ev}^{2} r$

(b) $\frac{1}{2} evr$

(c) $\frac{1}{2} {evr}^{2}$

(d) $\frac{1}{2} e^{2} v^{2} r$

57.

What is the value of gyromagnetic ratio ?

(a)	$8.8 \times 10^{11} \frac{C}{kg}$
(b)	$8.8 \times 10^{10} \frac{C}{kg}$
(c)	$8.8 \times 10^{8} \frac{C}{kg}$
(d)	$8.8 \times 10^{9} \frac{C}{kg}$

58.

An electron is moving round a nucleus. Its frequency is 10¹⁴Hz. Find the current I associated with this motion.

(a) 1.6 × 10^-3 A

(b) 1.6 × 10^-4 A

(c) 1.6 × 10^-5 A

(d) 1.6 × 10^-2 A

59.

In a bar magnet, 2L' is geometric length and 2L is magnetic length, then _____ .

(a) 2L' > 2L

(b) 2L' = 2L

(c) 2L' < 2L

(d) 2L' < 2(2L)

60.

Give the relation between geometric length (l_g) and magnetic length (l_m of a bar magnet.

(a)	$l_{m} = \frac{5}{6} l_{g}$
(b)	$2 l_{m} = \frac{5}{6} l_{g}$
(c)	$l_{m} = \frac{6}{5} l_{g}$
(d)	$l_{m} = \frac{3}{5} l_{g}$

Showing 51 to 60 out of 145 Questions