Advertisements
Advertisements
प्रश्न
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is
विकल्प
`"hc"/λ - "m"_"e" + ("e"^2"B"^2"R"^2)/(2"m"_"e")`
`"hc"/λ + 2"m"_"e" ["eBR"/(2"m"_"e")]^2`
`"hc"/λ - "m"_"e""c"^2 - ("e"^2"B"^2"R"^2)/(2"m"_"e")`
`"hc"/λ - 2"m"_"e" ["eBR"/(2"m"_"e")]^2`
उत्तर
`"hc"/λ - 2"m"_"e" ["eBR"/(2"m"_"e")]^2`
APPEARS IN
संबंधित प्रश्न
A photoelectric surface is illuminated successively by monochromatic light of wavelength λ and `λ/2`. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the material is
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is __________.
The work functions for metals A, B and C are 1.92 eV, 2.0 eV and 5.0 eV respectively. The metal/metals which will emit photoelectrons for a radiation of wavelength 4100Å is/are
Give the definition of intensity of light according to quantum concept and its unit.
Briefly discuss the observations of Hertz, Hallwachs and Lenard.
Explain the effect of potential difference on photoelectric current.
How many photons per second emanate from a 50 mW laser of 640 nm?
When a light of frequency 9 × 1014 Hz is incident on a metal surface, photoelectrons are emitted with a maximum speed of 8 × 105 ms−1. Determine the threshold frequency of the surface.
When a 6000 Å light falls on the cathode of a photo cell, photoemission takes place. If a potential of 0.8 V is required to stop emission of electron, then determine the
- frequency of the light
- energy of the incident photon
- work function of the cathode material
- threshold frequency and
- net energy of the electron after it leaves the surface.
At the given point of time, the earth receives energy from the sun at 4 cal cm–2 min–1. Determine the number of photons received on the surface of the Earth per cm2 per minute. (Given: Mean wavelength of sunlight = 5500 Å)
