# The number of photons per second on an average emitted by a source of monochromatic light of wavelength $$600~\text{nm}$$, when it delivers the power of $$3.3\times 10^{-3}$$ watt will be: $$(h = 6.6\times10^{-34}~\text{J-s})$$ 1. $$10^{16}$$ 2. $$10^{15}$$ 3. $$10^{18}$$ 4. $$10^{17}$$

Subtopic:  Particle Nature of Light |
64%
From NCERT
NEET - 2021
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An electromagnetic wave of wavelength $$\lambda$$ is incident on a photosensitive surface of negligible work function. If '$$m$$' is the mass of photoelectron emitted from the surface and $$\lambda_d$$ is the de-Broglie wavelength, then:
1. $$\lambda=\left(\frac{2 {mc}}{{h}}\right) \lambda_{{d}}^2$$
2. $$\lambda=\left(\frac{2 {h}}{{mc}}\right) \lambda_{{d}}^2$$
3. $$\lambda=\left(\frac{2 {m}}{{hc}}\right) \lambda_{{d}}^2$$
4. $$\lambda_{{d}}=\left(\frac{2 {mc}}{{h}}\right) \lambda^2$$

Subtopic:  De-broglie Wavelength |
55%
From NCERT
NEET - 2021
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J.J. Thomson's cathode-ray tube experiment
demonstrated that:

 1 cathode rays are streams of negatively charged ions 2 all the mass of an atom is essentially in the nucleus 3 the e/m of electrons is much greater than the e/m of protons 4 the e/m ratio of the cathode ray particles changes when a different gas is placed in the discharge tube
Subtopic:  Electron Emission |
53%
From NCERT
AIPMT - 2003
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A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then:

 1 each emitted electron carries one-quarter of the initial energy 2 number of electrons emitted is half the initial number 3 each emitted electron carries half the initial energy 4 number of electrons emitted is a quarter of the initial number
Subtopic:  Photoelectric Effect: Experiment |
66%
From NCERT
AIPMT - 2003
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A photo-cell is illuminated by a source of light, which is placed at a distance $$d$$ from the cell. If the distance becomes $$\frac{d}{2}$$, then the number of electrons emitted per second will be:
1. same
2. four times
3. two times
4. one-fourth

Subtopic:  Photoelectric Effect: Experiment |
71%
From NCERT
AIPMT - 2001
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Which one among the following shows the particle nature of light?
1. Photoelectric effect
2. Interference
3. Refraction
4. Polarisation

Subtopic:  Particle Nature of Light |
90%
From NCERT
AIPMT - 2001
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Which of the following is not the property of cathode rays:

 1 it produces a heating effect. 2 it does not deflect in the electric field. 3 it casts a shadow. 4 it produces fluorescence.
Subtopic:  Electron Emission |
67%
From NCERT
AIPMT - 2002
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When ultraviolet rays strike a metal plate, the photoelectric effect does not occur. It occurs by the incidence of:

1. Infrared rays

2. X-rays

4. Lightwave

Subtopic:  Photoelectric Effect: Experiment |
66%
From NCERT
AIPMT - 2002
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If particles are moving with the same velocity, then the de-Broglie wavelength is maximum for:
1. proton
2. $$\alpha-$$particle
3. neutron
4. $$\beta-$$particle

Subtopic:  De-broglie Wavelength |
63%
From NCERT
AIPMT - 2002
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The value of Planck's constant is:

1. $6.63×{10}^{-34}$ $\mathrm{J}/\mathrm{s}$

2. $6.63×{10}^{-34}$ $\mathrm{kg}-{\mathrm{m}}^{2}/\mathrm{s}$

3. $6.63×{10}^{-34}$ $\mathrm{kg}-{\mathrm{m}}^{2}$

4.

Subtopic:  Einstein's Photoelectric Equation |
58%
From NCERT
AIPMT - 2002
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