Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speed of emitted electrons will be […]
In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by
Options
(a) increasing the potential difference between the anode and filament (b) increasing the […]
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
Options
(a) 540 nm (b) 400 nm (c) 310 nm […]
Photoelectric emision occurs only when the incident light has more than a certain minimum
Options
(a) power (b) wavelength (c) intensity (d) frequency
Correct Answer:
frequency
Explanation:
For occurence of photoelectric effect, the […]
Order of e/m ratio of proton, α-particle and electron is
Options
(a) e>p>α (b) p>α>e (c) e>α>p (d) None of these
Correct Answer:
e>p>α
Explanation:
For electron (e / mₑ) = 1.6 × 10⁻¹⁹ […]
The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work function 5.01 eV, when ultraviolet light of 200 nm falls on it, must be:
Options […]
The minimum wavelength of X-rays produced in a Collidge tube operated at potential difference of 40 kV is
Options
(a) 0.31 Å (b) 3.1 Å (c) 31 Å (d) 311 Å
Correct Answer: […]
Source S₁ is producing, 10¹⁵ photons per second of wavelength 5000Å. Another source S₂ is producing 1.02 x 10¹⁵ photons per second of wavelength 5100Å Then, (power of S₂) (power of S₁) is equal to: […]
X-rays when incident on a metal
Options
(a) Exert force, Transfer energy and Transfer pressure on it (b) Transfer energy only to it (c) Transfer pressure only to it (d) Exert a force […]
Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a large irradiated by this […]
2017 Copyright Doctor Dreams Training Academy