The energy of a quanta of frequency Hz and will be:
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2.
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4.
The spectrum of radiation 1.0 x 1014 Hz is in the infrared region.
The energy of one photon of this in joules will be:
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2.
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4.
A helium-neon laser produces monochromatic light of a wavelength of 667 nm. The power emitted is 9 mW. The average number of photons arriving per second on average at a target irradiated by this beam is:
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A source S1 is producing, 1015 photons per sec of wavelength 5000 Å. Another source S2 is producing 1.02×1015 photons per second of wavelength 5100 Å. Then the ratio of the power of S2 to the power of S1 is equal to:
1. | 1.00 | 2. | 1.02 |
3. | 1.04 | 4. | 0.98 |
A 200 W sodium street lamp emits yellow light of wavelength 0.6 . If it is 25% efficient in converting electrical energy to light, how many photons of yellow light does it emit per second?
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Monochromatic light of frequency 6.0×1014 Hz is produced by a laser. The power emitted is 2×10-3 W. What will be the average number of photons emitted by the source per second?
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Assertion (A): | Mass of a moving photon varies inversely to the wavelength. |
Reason (R): | \(\times\)(speed of light)2. | Energy of the particle = Mass
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | A photon has no rest mass, yet it carries definite momentum. |
Reason (R): | Momentum of a photon is due to its energy and hence its equivalent mass. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |