21. |
De Broglie wavelength of a proton and α-particle is same, _____ physical quantity should be same for both.
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Answer:
Option (d) |
22. |
To reduce de Broglie wavelength of an electron from 10-10 m to 0.5 × 10-10 m, its energy should be _____
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Answer:
Option (a) |
23. |
The de-Broglie wavelength of a proton and α-particle is same. The ratio of their velocities will be _____ .
[α-particle is the He-nucleus, having two protons and two neutrons. Thus, its mass mα ≈ 4 mp; where mp is the mass of the proton.]
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Answer:
Option (d) |
24. |
The de-Broglie wavelength associated with a particle with rest mass m0 and moving with speed of light in vacuum is _____ .
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Answer:
Option (b) |
25. |
An image of sun is formed by convex lens of focal length 40 cm on the metal surface of a photoelectric cell, and a photoelectric current I is produced. If now another lens with half the focal length but with same diameter is used to focus the sun image, on the photoelectric cell, photoelectric current becomes _____ .
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Answer:
Option (c) |
26. |
Cathode rays.....
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Answer:
Option (d) |
27. |
Degrees of freedom of harmonic oscillator = _____ .
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Answer:
Option (a) |
28. |
The velocity of photon emitted in photoelectric effect depends on the properties of photosensitive surface and .....
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Answer:
Option (a) |
29. |
Photoelectric effect represents that .....
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Answer:
Option (b) |
30. |
De-Broglic wavelength of a particle moving with velocity is same as the wavelength of photon. The ratio of kinetic energy of the particle to the energy of photon is .....
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Answer:
Option (b) |