- ADecreases directly as the distance from the centre.
- BIncreases directly as the distance from the centre.
- CRemains constant.
- DNone of these.
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The electric potential V at any point O (x, y, z all in metres) in space is given by
. The electric field at the point (1m,0, 2m) in volt/metre is
|
(a) 8 along negative X - axis |
(b) 8 along positive X - axis |
|
(c) 16 along negative X - axis |
(d) 16 along positive Z - axis |
An object of length 6 cm is placed on the principle axis of a concave mirror of focal length f at a distance of 4f. The length of the image will be
|
(a) 2 cm |
(b) 12 cm |
(c) 4 cm |
(d) 1.2 cm |
Assertion : Amongst alpha, beta and gamma rays, a-particle has maximum penetrating power.
Reason : The alpha particle is heavier than beta and gamma rays.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
The decay constant of radium is 4.28
per year. Its half life will be
|
(a) 2000 years |
(b) 1240 years |
(c) 63 years |
(d) 1620 years |
The energy liberated on complete fission of 1 kg of
is (Assume 200 MeV energy is liberated on fission of 1 nucleus)
|
(a) 8.2 |
(b) 8.2 |
(c) 8.2 |
(d) 8.2 |
Doppler's effect in sound in addition to relative velocity between source and observer, also depends while source and observer or both are moving. Doppler effect in light depend only on the relative velocity of source and observer. The reason of this is
|
(a) Einstein mass - energy relation |
(b) Einstein theory of relativity |
|
(c) Photoelectric effect |
(d) None of these |