Advertisements
Advertisements
प्रश्न
The wavelength λe of an electron and λp of a photon of same energy E are related by ______.
विकल्प
λp ∝ λe
`λ_p ∝ sqrt(lambda_e)`
`λ_p ∝ 1/sqrt(lambda_e)`
`λ_p ∝ lambda_e^2`
Advertisements
उत्तर
The wavelength λe of an electron and λp of a photon of same energy E are related by `bbunderline(lambda_p prop lambda_e^2)`.
संबंधित प्रश्न
Find the (a) maximum frequency and (b) minimum wavelength of X-rays produced by 30 kV electrons.
The work function of caesium metal is 2.14 eV. When light of frequency 6 × 1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the
- maximum kinetic energy of the emitted electrons,
- Stopping potential, and
- maximum speed of the emitted photoelectrons?
How does one explain the emission of electrons from a photosensitive surface with the help of Einstein's photoelectric equation?
Let i0 be the thermionic current from a metal surface when the absolute temperature of the surface is T0. The temperature is slowly increased and the thermionic current is measured as a function of temperature. Which of the following plots may represent the variation in (i/i0) against (T/T0)?

The constant A in the Richardson−Dushman equation for tungsten is 60 × 104 A m−2K−2. The work function of tungsten is 4.5 eV. A tungsten cathode with a surface area 2.0 × 10−5 m2 is heated by a 24 W electric heater. In steady state, the heat radiated by the heater and the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan's Constant = 6 × 10−8 W m−2 K−1. Assume that the thermions take only a small fraction of the heat supplied.
Answer the following question.
Define the term "Threshold frequency", in the context of photoelectric emission.
The wave associated with a moving particle of mass 3 × 10–6 g has the same wavelength as an electron moving with a velocity 6 × 106 ms–1. The velocity of the particle is
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is (Take h = 6.6 × 10–34 Js)
What do you mean by electron emission? Explain briefly various methods of electron emission.
A 150 W lamp emits light of the mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.
