- AHertz
- BPlanck
- CMillikan
- DEinstein
Explanation:
Einstein showed mathematically, the energy of the incoming photons was precisely related to the frequency or wavelength of the light shining and equal to the energy of the electrons they ejected. Einstein's explanation of the photoelectric effect was powerful evidence that energy could exist only in fixed amounts called quanta.
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Which of the following is not reversible
|
(a) Joule effect |
(b) Peltier effect |
(c) Seebeck effect |
(d) Thomson effect |
In an X-rays tube, the intensity of the emitted X-rays beam is increased by
| (a) Increasing the filament current | (b) Decreasing the filament current |
|
(c) Increasing the target potential |
(d) Decreasing the target potential |
A lens which has focal length of 4 cm and refractive index of 1.4 is immersed in a liquid of refractive index 1.6, then the focal length will be
|
(a) – 12.8 cm |
(b) 32 cm |
(c) 12.8 cm |
(d) – 32 cm |
In the case of constants a and b of a transistor
|
(a) a = b |
(b) b < 1 a > 1 |
(c) ab = 1 |
(d) b > 1 a < 1 |
The torque on a bar magnet due to the earth's magnetic field is maximum when the axis of the magnet is
|
(a) Perpendicular to the field of the earth |
|
(b) Parallel to the vertical component of the earth's field |
|
(c) At an angle of 33o with respect to the N-S direction |
|
(d) Along the North-South (N-S) direction |
Assertion : Owls can move freely during night.
Reason : They have large number of rods on their retina.
|
(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. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
In an electroplating experiment, m gm of silver is deposited when 4 ampere of current flows for 2 minute. The amount (in gm) of silver deposited by 6 ampere of current for 40 second will be
|
(a) 4 m |
(b) m/2 |
(c) m/4 |
(d) 2 m |

