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
(a) 16 V
(b) 10V
(c) 12V
(d) 8V
(b) 10V
The magnetic flux linked with a coil is given by an equation Φ = 5t² + 2t + 3. The induced e.m.f. in the coil at the third second will be
(A) 32 units
(B) 54 units
(C) 40 units
(D) 65 units
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
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
The SI unit of inductance is the henry. It can be written as
(a) weber/ampere
(b) volt-second/ampere
(c) joul/(ampere)²
(d) ohm-second
The direction of induced emf during electromagnetic induction is given by
(a) Faraday’s law
(b) Lenz’s law
(c) Maxwell’s law
(d) Ampere’s law
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
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
A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will
(A) Increase four times
(B) be reduced to half
(C) remain the same
(D) Be doubled
In Young’s double slit experiment, the fringe width is β . If the entire arrangement is now placed inside a liquid of refractive index μ , the fringe width will become
(a) μ β
(b) β/μ
(c) β/μ+1
(d) β/μ−1
An optically active compound
(a) rotates the plane of polarised light.
(b) changes the direction of polarised light.
(c) does not allow plane polarised light to pass through.
(d) none of these.
Wavefront generated from a line source is
a. Cylindrical wavefront
b. Spherical wavefront
c. Plane front
d. Either a.) or b.)
Four point charges –Q,-q,2q,2Q are placed at different corners of a square . The relation between Q and q for which the potential at the center of the square is zero
1.Q=q
2.Q=1/q
3.Q=-q
4. Q=-1/q
For sustained interference, we need two sources which emit radiations:
(a) of the same intensity
(b) of the same amplitude
(c) having a constant phase difference
(d) None of these
A young’s double slit experiment uses a monochromatic source. The shape of interference fringes formed on a screen is :
a. Parabola
b. straight line
c. circle
d. Hyperbola