When a piece of metal is illuminated by a monochromatic light of wavelength λ, then stopping potential is 3Vs. When same surface is illuminated by light of wavelength 2λ, then stopping potential becomes Vs. The […]
In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of
Options
(a) Collisions between the charged paricles emitted from the cathode […]
Photon of frequency ν has a momentum associated with it. If c is the velocity of light, the momentum is
Options
(a) hν/c (b) ν/c (c) hνc (d) hνc²
Correct Answer:
hν/c
Explanation: […]
What is the energy of He⁺ electron in first orbit?
Options
(a) (40.8 eV) (b) (-52.2 eV) (c) (-54.4 eV) (d) (-13.6 eV)
Correct Answer:
(-54.4 eV)
Explanation:
No explanation available. Be the […]
If h is Planck’s constant, the momentum of a photon of wavelength 0.01 Å is
Options
(a) 10⁻² h (b) h (c) 10² h (d) 10¹² h
Correct Answer:
10¹² h
Explanation:
No […]
If the velocity of an electron increases, then its de Broglie wavelength will
Options
(a) Increase (b) Decrease (c) Remain the same (d) Become twice
Correct Answer:
Decrease
Explanation:
No explanation available. Be […]
If the radioactive dacay constant of radium is 1.07 x 10⁻⁴ year⁻¹, then its half-life is approximately
Options
(a) 8900 years (b) 7000 years (c) 6477 years (d) 5000 years
Correct Answer:
6477 […]
The electromagnetic theory of light failed to explain
Options
(a) Photoelectric effect (b) polarisation (c) diffraction interference (d)
Correct Answer:
Photoelectric effect
Explanation:
No explanation available. Be the first to write the […]
The Priniple of LASER action involves
Options
(a) Amplification of particular frequency emitted by the system (b) Population inversion (c) Stimulated emission (d) All of these
Correct Answer:
All of these
Explanation:
No […]
The time by a photoelectron to come out after the photon strikes is approximately
Options
(a) 10⁻¹ s (b) 10⁻⁴ s (c) 10⁻¹⁰ s (d) 10⁻¹⁶s
Correct Answer:
10⁻¹⁰ s
Explanation:
Emission of photo-electron […]
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