The energy of quanta of frequency \(10^{15}~\text{Hz}\) and \(h = 6.6 \times 10^{-34}~\text{J-s}\) will be:
1. \(6.6\times 10^{-19}~\text{J}\)
2. \(6.6\times 10^{-12}~\text{J}\)
3. \(6.6\times 10^{-49}~\text{J}\)
4. \(6.6\times 10^{-41}~\text{J}\)

Subtopic:  Particle Nature of Light |
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The spectrum of radiation \(1.0\times 10^{14}\) Hz is in the infrared region. The energy of one photon of this in joules will be:
1. \(6.62\times 10^{-48}\)
2. \(6.62\times 10^{-20}\)
3. \(\frac{6.62}{3}\times 10^{-28}\)
4. \(3\times 6.62\times 10^{-28}\)

Subtopic:  Particle Nature of Light |
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A helium-neon laser produces monochromatic light of a wavelength of \(667~\text{nm}.\) The power emitted is \(9~\text{mW}.\) The average number of photons arriving per second on average at a target irradiated by this beam is:
1. \(9\times 10^{17}\)
2. \(3\times 10^{16}\)
3. \(9\times 10^{15}\)
4. \(3\times 10^{19}\)

Subtopic:  Particle Nature of Light |
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Level 1: 80%+
NEET - 2009
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A source \(S_1\) is producing, \(10^{15}\) photons per sec of wavelength \(5000~\mathring{A}.\) Another source \(S_2\) is producing \(1.02\times 10^{15}\) photons per second of wavelength \(5100~\mathring{A}.\) Then the ratio of the power of \(S_2\) to the power of \(S_1\) is equal to:
1. \(1.00\) 2. \(1.02\)
3. \(1.04\) 4. \(0.98\)
Subtopic:  Particle Nature of Light |
 77%
Level 2: 60%+
AIPMT - 2010
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A \(200~\text{W}\) sodium street lamp emits yellow light of wavelength \(0.6~\mu\text{m}\). If it is \(25\%\) efficient in converting electrical energy to light, how many photons of yellow light does it emit per second?
1. \(1.5\times 10^{20}\)
2. \(6\times 10^{18}\)
3. \(62\times 10^{20}\)
4. \(3\times 10^{19}\)

Subtopic:  Particle Nature of Light |
 74%
Level 2: 60%+
AIPMT - 2012
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Monochromatic light of frequency \(6.0\times 10^{14}\) Hz is produced by a laser. The power emitted is \(2\times 10^{-3}\) W. What will be the average number of photons emitted by the source per second?
1. \(5\times 10^{15}\)
2. \(5\times 10^{16}\)
3. \(5\times 10^{17}\)
4. \(5\times 10^{14}\)

Subtopic:  Particle Nature of Light |
 75%
Level 2: 60%+
AIPMT - 2007
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Given below are two statements: 
Assertion (A): Mass of a moving photon varies inversely to the wavelength.
Reason (R): Energy of the particle = Mass\(\times\)(speed of light)2.
 
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.
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Given below are two statements: 
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.
Subtopic:  Particle Nature of Light |
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Level 1: 80%+
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