MCQs of Moving Charges & Magnetism

Moving Charges & Magnetism MCQs

MCQs of Moving Charges & Magnetism

Showing 71 to 80 out of 123 Questions

71.

When current is passed through a circular wire prepared from a long conduction wire, magnetic field produced at its centre is B. Now , a loop having two turns is prepared from the same wire and the same current is passed through it. The magnetic field at its centre will be _____ .

(a)	$\frac{B}{4}$
(b)	$\frac{B}{1}$
(c)	4B
(d)	2B

72.

A proton, a deuteron and an α-particle with the same kinetic energy enter a region of uniform magnetic field moving at right angles to B. What is the ration of the radii of their circular paths ?

(a)	$\sqrt{2} : \sqrt{2} : 1$
(b)	$\sqrt{2} : 1 : 1$
(c)	$1 : \sqrt{2} : 1$
(d)	$1 : \sqrt{2} : \sqrt{2}$

73.

The SI unit of magnetic moment is _____.

(a)	JT^-1
(b)	TJ^-1
(c)	A^-1m²
(d)	Am^-2

74.

To send 10% of main current through a moving coil galvanometer of resistance 99 Ω, the shunt required is _____.

(a)	9Ω
(b)	11Ω
(c)	10Ω
(d)	9.9Ω

75.

The resistance of ideal voltmeter is _____.

(a)	Zero
(b)	greater then zero but finite value
(c)	infinite
(d)	5000Ω

76.

A particle of mass m carrying charge 'q' is accelerated by a potential difference V. It enters perpendicularly a region of uniform magnetic field B and executes circular motion on circumference of radius R, then what will be the (ratio) q/m ?

(a)	$\frac{2 V}{B^{2} R^{2}}$
(b)	$\frac{V}{2 B R}$
(c)	$\frac{V B}{2 R}$
(d)	$\frac{m V}{B R}$

77.

The force existing between two parallel current carrying conductors is F. If the current in each conductor is halved, then the value of force will be _____.

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

78.

The magnetic field due to current carrying circular loop of radius 6 cm at a point on the axis at a distance 8 cm from the centre is 216 μT. What will be its value at the centre of the loop ?

(a)	250 μT
(b)	500 μT
(c)	1000 μT
(d)	432 μT

79.

A long horizontal wire 'A' carries a current of 10 A. It is righdly fixed. Another small wire 'B' is placed just above and parallel to 'A' in air. The weight of wire B per unit length is 40 ×10^-3 Nm^-1 and carries a current of 20 A. Find the distance of wire B from A, so that wire B remains in stationary equilibrium condition of current in B w.r.t. A.

(a)	1×10^-3 m; mutually opposite direction.
(b)	2×10^-3 m; in same direction.
(c)	$\frac{1}{2}$ ×10^-3 m; mutually opposite direction.
(d)	$\frac{1}{3}$ ×10^-3 m; in same direction.

80.

For the galvanometer, working as a voltmeter _____ is connected with the coil of the galvanometer.

(a)	high resistance in parallel
(b)	low resistance in parallel
(c)	high resistance in series
(d)	low resistance in series

Showing 71 to 80 out of 123 Questions