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
(a) weber/ampere
(b) volt-second/ampere
(c) joul/(ampere)²
(d) ohm-second
(b) volt-second/ampere
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
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
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 self inductance of long solenoid cannot be increased by
(a) increasing its area of cross section
(b) increasing its length
(c) changing the medium with grater permeability
(d) Increasing the current through it.
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 capacitor is connected across a battery and the plate separation of capacitor is increased without removing the battery, then:
(a) capacitance will increase
(b) charge stored will increase
(c) energy stored will decrease
(d) potential difference will increase
Two sources of intensity I and 4I are used in an interference experiment . Find the intensity at points where waves from two sources superimpose with phase difference π/2 is
I. 4I
II. 6I
III. 5I
IV. 9I
When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
(a) zero..
(b) π.
(c) π/2.
(d) 2π.
If the angle of dip at two places are 30° and 45° respectively, then the ratio of horizontal components of the earth’s magnetic field at the two places will be
Unpolarized light is incident on a plane glass surface The angle of incidence so that reflected and refracted rays are perpendicular to each other, them
(a) tan iβ= μ/2
(b) tan iβ = μ
(c) sin iβ = μ
(d) cos iβ = μ
What happen when we use white light in Young’s double slit experiment.
(A) No interference pattern will form
(B) white fringes will form
(C) Central bright fringe will be white
(D) Central fringe will be coloured
Colours appears on a thin film of soap and a soap bubble is due to
(A) Interference
(B) Diffraction
(C) Polarisation
(D) Refraction