A conducting loop of area 5.0 cm² is placed in a magnetic field which varies sinusoidally with time as B=0.2 sin300t. The normal to the coil makes an angle of 60° with the field. The emf induced at t=(π/900)s
(a) 7.5 × 10⁻³ V
(b) Zero
(c) 15 × 10⁻³ V
(d) 20 × 10⁻³ V
(a) 7.5 × 10⁻³ V
(b) Zero
(c) 15 × 10⁻³ V
(d) 20 × 10⁻³ V
(a) 7.5 × 10⁻³ V
A conducting rod of unit length moves with a velocity 10 m/s in a direction perpendicular to its length and perpendicular to a uniform magnetic field of magnitude 0.2 T. The emf induced between the ends of the rod is
(a) 4 V
(b) 2V
(c) 1V
(d) Zero
In a circuit with a coil of resistance 3Ω, the magnetic flux changes from 1.0 Wb to 10.0 Wb in 0.3 s. The charge that flows in the coil during this time is
(a) 2.0 C
(b) 3.0 C
(c) 4.0 C
(d) 1.0 C
A coil of wire of certain radius has 500 turns and self inductance of 75 mH. The self inductance of a second similar coil of 600 turns will be
(a) 100 mH
(b) 150mH
(c) 108 mH
(d) 105mH
A square loop of side l , resistance R is placed in a uniform magnetic field B acting normally to the plane of the loop. If we attempt to pull it out of the field with a constant velocity v , then the power needed is
(a) BRlv
(b) B²l²v²/R
(c) B l²v²/ R
(d) Blv/R
Two currents loops are concentric and lie in the same plane. The current in the outer loop is anti clockwise and increasing with time. The induced current in the inner loop ,is
(a) Clockwise
(b) Zero
(c) Counter-clockwise
(d) None of these
A long solenoid has 2000 turns. When a current of 2 A flows through it, then the magnetic flux linked with each turn of the solenoid is 2 × 10⁻³ Wb. The self inductance of the solenoid is
(a) 1 H
(b) 2 H
(c) 3 H
(d) 4 H
The magnetic flux linked with a coil is given by the equation Ø = 2t² + 2t + 4 weber. The magnitude of induced emf at time t=2s will be
(a) 16 V
(b) 10V
(c) 12V
(d) 8V
Length of a hollow tube is 5 m, its outer diameter is 10 cm and thickness of its wall is 5 mm. If resistivity of the material of the tube is 1.7 x 10⁻⁸ Ωm, then the resistance of the tube will be
(a) 5.6 × 10⁻⁵ Ω
(b) 2 × 10⁻⁵ Ω
(c) 4 × 10⁻⁵ Ω
(d) None of these
A wavefront of a wave has direction with wave motion
(A) Parallel
(B) Perpendicular
(C) opposite
(D) at any angle θ
When 2 × \(10^{11}\) electrons are removed from a neutral metal sphere, the charge on the sphere becomes:
(A) -16 nC
(B) 16 nC
(C) -32 nC
(D) 32nC
Two coherent monochromatic light beams of intensities I and 41 superimpose. The maximum and minimum possible intensities in the resulting beam are:
(a) 5I and I
(b) 5I and 3I
(c) 3I and I
(d) 9I and I
A bar magnet of dipole moment ’m’ cut into two equal pieces transverse to its length. Dipole moment of each part is
a) Remain same
b) m/2
c) 2m
d) none of the above
A dip circle is so set that it moves freely in the magnetic meridian. The angle of dip is 40°. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30° with the magnetic meridian. In this position, the needle will dip by the angle
The interference phenomenon takes place
I. In all waves
II. In transverse waves only
III. In longitudinal waves only
IV. In standing waves only