MCQs of Magnetism and Matter

Magnetism and Matter MCQs

MCQs of Magnetism and Matter

Showing 81 to 90 out of 145 Questions

81.

When a current carrying loop is replaced by an equivalent magnetic dipole _____ .

(a)	the distance l between the poles is fixed
(b)	the pole strength p of each pole is fixed
(c)	the dipole moment is reversed.
(d)	the product pl is fixed.

82.

Let r be the distance of a point on the axis of a bar magnet from its centre. The magnetic field at r is always proportional to

(a)	$\frac{1}{r^{2}}$
(b)	$\frac{1}{r^{3}}$
(c)	$\frac{1}{r}$
(d)	$not necessarily \frac{1}{r^{3}} at all points$

83.

Magnetic meridian is a plane _____ .

(a)	perpendicular to magnetic axis of Earth.
(b)	perpendicular to geographic axis of Earth.
(c)	passing through the magnetic axis of Earth.
(d)	passing through the geographic axis.

84.

At geomagnetic pole, a magnetic needle allowed to rotate in horizontal plane will _____

(a)	stay in north - south direction only.
(b)	stay in any position.
(c)	stay in east - west direction only.
(d)	become rigid showing no movement.

85.

The horizontal and vertical components of magnetic field of Earth are same at some place on the surface of Earth. The magnetic dip angle at this place will be _____ .

(a)	30°
(b)	45°
(c)	0°
(d)	90°

86.

Inside a bar magnet, the magnetic field lines ______

(a)	are not present.
(b)	are parallel to the cross - sectional area of the magnet.
(c)	are in the direction from N - pole to S - pole.
(d)	are in the direction from S - pole to N - pole.

87.

A straight steel wire of length l has magnetic moment m. If the wire is bent in the form of a semicircle, the new value of the magnetic dipole moment is _____ .

(a)	m
(b)	$\frac{2 m}{π}$
(c)	$\frac{m}{2}$
(d)	$\frac{m}{π}$

88.

At a place on Earth, the horizontal component of Earth's magnetic field is

\sqrt{3}

times vertical component. The angle of dip at this place is _____ .

(a)	0
(b)	$\frac{π}{2} r a d$
(c)	$\frac{π}{3} r a d$
(d)	$\frac{π}{6} r a d$

89.

A place, where the vertical component of Earth's magnetic field is zero has the angle of dip angle equal to _____ .

(a)	0°
(b)	45°
(c)	60°
(d)	90°

90.

A place where the horizontal component of Earth's magnetic field is zero lies at _____

(a)	geographic equator
(b)	geomagnetic equator
(c)	one of the geographic poles
(d)	one of the geomagnetic poles

Showing 81 to 90 out of 145 Questions