An electron of mass m with an initial velocity \((v_o>0)\) enters in an electric field (Eo = constant>0) at t=0. If , is its de-Broglie wavelength initially, then what will be its de-Broglie wavelength at time t?
When the light of frequency \(2\nu_0\) (where \(\nu_0\) is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is v1. When the frequency of the incident radiation is increased to \(5\nu_0,\) the maximum velocity of electrons emitted from the same plate is v2. What will be the ratio of v1 to v2?
1. 1 : 2
2. 1 : 4
3. 4 : 1
4. 2 : 1
What is the de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature T (Kelvin) and mass m?
The photoelectric threshold wavelength of silver is 3250 x 10-10 m. What will be the velocity of the electron ejected from a silver surface by the ultraviolet light of wavelength 2536 x 10-10 m?
(Given h= and )
4. \(\approx 0.3\times 10^5\) ms-1
If an electron of mass m with a de-Broglie wavelength of \(\lambda\) falls on the target in an X-ray tube, the cut-off wavelength ( λ0) of the emitted X-ray will be:
Photons with energy 5 eV are incident on a cathode C in a photoelectric cell. The maximum energy of emitted photoelectrons is 2 eV. When photons of energy 6 eV are incident on C, no photoelectron will reach the anode A, if the stopping potential of A relative to C is:
1. +3 V
2. +4 V
3. - 1V
4. -3 V
When a metallic surface is illuminated with radiation of wavelength , the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2, the stopping potential is .The threshold wavelength for metallic surface is:
(a) 5 (b)
(c) 3 (d) 4
An electron of mass m and a photon have the same energy E. Find the ratio of de-Broglie wavelength associated with the electron to that associated with the photon. (c is the velocity of light)