- AThe electric field is uniform.
- BThe electric field is zero.
- CThe electric field shall necessarily change if a charge is placed outside the region.
- DNone of these.
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When wavelength of incident photon is decreased then
|
(a) Velocity of emitted photo-electron decreases |
|
(b) Velocity of emitted photoelectron increases |
|
(c) Velocity of photoelectron do not charge |
|
(d) Photo electric current increases |
Consider the charge configuration and spherical Gaussian surface as shown in the figure. When calculating the flux of the electric field over the spherical surface the electric field will be due to

|
(a) |
(b) Only the positive charges |
|
(c) All the charges |
(d) + |
If the work function of a photometal is 6.825 eV. Its threshold wavelength will be (c = 3 ![]()
|
(a) 1200 Å |
(b) 1800 Å |
(c) 2400 Å |
(d) 3600 Å |
and
are the electrical conductivities of Ge and Na respectively. If these substances are heated, then
|
(a) Both |
(b) |
|
(c) |
(d) Both |
Two resistances and
when connected in series and parallel with 120 V line, power consumed will be 25 W and 100 W respectively. Then the ratio of power consumed by
to that consumed by
will be
|
(a) 1 : 1 |
(b) 1 : 2 |
(c) 2 : 1 |
(d) 1 : 4 |
Two long parallel wires carrying equal current separated by 1m, exert a force of 2 on one another. The current flowing through them is
|
(a) 2.0 A |
(b) 2.0 |
(c) 1.0 A |
(d) 1.0 |
A metal rod moves at a constant velocity in a direction perpendicular to its length. A constant uniform magnetic field exists in space in a direction perpendicular to the rod as well as its velocity. Select the correct statement(s) from the following
|
(a) The entire rod is at the same electric potential |
|
(b) There is an electric field in the rod |
|
(c) The electric potential is highest at the centre of the rod and decreases towards its ends |
|
(d) The electric potential is lowest at the centre of the rod and increases towards its ends |