A parallel plate capacitor with air as medium between the plates has a capacitance of 10 μF. The area of capacitor is divided into two equal halves and filled with two media as shown in the figure having dielectric constant 
and 
. The capacitance of the system will now be
|
(a) 10 μF |
(b) 20 μF |
(c) 30 μF |
(d) 40 μF |
(c) 30 μF
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The stopping potential (
|
(a) Depends upon the angle of incident light |
|
(b) Depends upon the intensity of incident light |
|
(c) Depends upon the surface nature of the substance |
|
(d) Is independent of the intensity of the incident light |
Two different loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increasing with time. The induced current in the inner loop then, is
|
(a) Clockwise |
|
(b) Zero |
|
(c) Counter clockwise |
|
(d) In a direction that depends on the ratio of the loop radii |
The magnetic field of earth is due to
| (a) Motion and distribution of some material in and outside the earth |
| (b) Interaction of cosmic rays with the current of earth |
| (c) A magnetic dipole buried at the centre of the earth |
| (d) Induction effect of the sun |
The north and south poles of two identical magnets approach a coil, containing a condenser, with equal speeds from opposite sides. Then
|
(a) Plate 1 will be negative and plate 2 positive |
|
(b) Plate 1 will be positive and plate 2 negative |
|
(c) Both the plates will be positive |
|
(d) Both the plates will be negative |
From the graph between current I and voltage V shown below, identify the portion corresponding to negative resistance
|
(a) AB |
(b) BC |
(c) CD |
(d) DE |
Lenz's law is consequence of the law of conservation of
|
(a) Charge |
(b) Momentum |
(c) Mass |
(d) Energy |
A double convex lens is made of glass of refractive index 1.5. If its focal length is 30 cm, then radius of curvature of each of its curved surface is
|
(a) 10 cm |
(b) 15 cm |
(c) 18 cm |
(d) None of these |