Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a phototsensitive material. he stopping potential is measured to be 3.57 V. The threshold frequency of the materials […]
The work function for metals A,B abd C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein’s equation the metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are […]
The threshold frequency for a photosensitive metal is 3.3 x 10¹⁴ Hz. If light of frequency 8.2 x 10¹⁴ Hz incident on this metal, the cut-off voltage for the photoelectric emission is nearly
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In photoelectric emission process from a metal of work function, 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is
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(a) 1.8 V (b) 1.2 […]
Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased associated to 100 kV then the de-Broglie wavelength associated with the electrons would
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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
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(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
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(a) 540 nm (b) 400 nm (c) 310 nm […]
Photoelectric emision occurs only when the incident light has more than a certain minimum
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(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
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(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 […]
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