Light of a frequency of \(1.5\) times the threshold frequency is incident on a photosensitive material. What happens to the photoelectric current when the frequency is cut in half and the intensity is doubled?

1. four times 2. one-fourth
3. zero 4. doubled

Subtopic:  Photoelectric Effect: Experiment |
 53%
From NCERT
NEET - 2020
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An electron is accelerated from rest through a potential difference of \(V\) volt. If the de Broglie wavelength of an electron is \(1.227\times10^{-2}~\text{nm}\)what will be its potential difference?
1. \(10^{2}~\text{V}\)
2. \(10^{3}~\text{V}\)
3. \(10^{4}~\text{V}\)
4. \(10^{5}~\text{V}\)

Subtopic:  De-broglie Wavelength |
 58%
From NCERT
NEET - 2020
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An electron with \(144~\text{eV}\) of kinetic energy has a de-Broglie wavelength that is very similar to?
1. \(102\times10^{-3}~\text{nm}\)
2. \(102\times10^{-4}~\text{nm}\)
3. \(102\times10^{-5}~\text{nm}\)
4. \(102\times10^{-2}~\text{nm}\)

Subtopic:  De-broglie Wavelength |
 52%
From NCERT
NEET - 2020
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A proton and an \(\alpha\text{-}\)particle are accelerated from rest to the same energy. The de-Broglie wavelength \(\lambda_p\) and \(\lambda_\alpha\) are in the ratio:
1. \(2:1\)
2. \(1:1\)
3. \(\sqrt{2}:1\)
4. \(4:1\)

Subtopic:  De-broglie Wavelength |
 65%
From NCERT
NEET - 2019
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The work function of the photosensitive material is \(4.0~\text{eV}\). The longest wavelength of light that can cause photoelectric emission from the substance is (approximately):
1. \(3100~\text{nm}\)
2. \(966~\text{nm}\)
3. \(31~\text{nm}\)
4. \(310~\text{nm}\)

Subtopic:  Photoelectric Effect: Experiment |
 73%
From NCERT
NEET - 2019
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Two radiations of photons energies \(1\) eV and \(2.5\) eV, successively illuminate a photosensitive metallic surface of work function \(0.5\) eV. The ratio of the maximum speeds of the emitted electrons is:
1. \(1:2\)
2. \(1:1\)
3. \(1:5\) 
4. \(1:4\)

Subtopic:  Electron Emission |
 77%
From NCERT
AIPMT - 2012
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If the momentum of an electron is changed by \(P,\) then the de-Broglie wavelength associated with it changes by \(0.5\%.\) The initial momentum of an electron will be:
1. \(400P\)
2. \(\frac{P}{100}\)
3. \(100P\)
4. \(200P\)

Subtopic:  De-broglie Wavelength |
 68%
From NCERT
AIPMT - 2012
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The threshold frequency for a photosensitive metal is \(3.3\times10^{14}~\text{Hz}\). If the light of frequency \(8.2\times10^{14}~\text{Hz}\) is incident on this metal, the cutoff voltage for the photoelectric emission will be:
1. \(1~\text{V}\)
2. \(2~\text{V}\)
3. \(3~\text{V}\)
4. \(5~\text{V}\)

Subtopic:  Einstein's Photoelectric Equation |
 69%
From NCERT
AIPMT - 2011
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When monochromatic radiation of intensity I falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2I, the number of emitted electrons and their maximum kinetic energy are respectively:

1. 2N and T

2. 2N and 2T

3. N and T

4. N and 2T

Subtopic:  Electron Emission |
 83%
From NCERT
AIPMT - 2010
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What did Einstein prove by the photo-electric effect?

1. E = h\(\nu\)

2. KE=12mv2

3. E=mc2

4. E=-Rhc2n2

Subtopic:  Einstein's Photoelectric Equation |
 59%
From NCERT
AIPMT - 2000
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