Find the de Broglie wavelength associated with an electron moving with velocity 0.6c. Given, rest mass of electron = \(9.1\times { 10 }^{ -31 }kg\) ,\(h=6.63\times { 10 }^{ -34 }Js\)

An electron, \(\alpha \) -particle and a proton have the same de-Broglie wavelengths. Which of
theseparticle has
(i) minimum kinetic energy?
(ii) maximum kinetic energy and why?
In what way has the wave nature of electron beam exploited in an electron microscope?

A student performs an experiment on photoelectric effect, using two materials A and B. A plot of V_stop versus v is given in the figure.
(i) Which material A or B has a higher work function?

(ii) Given the electric charge of an electron =\(1.6\times { 10 }^{ -19 }C\), find the value of h obtained from the experiment for both A and B.
Comment on whether it is consistent with the Einstein's theory.

Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work functions W₀₁ and W₀₂ (W₀₁> W₀₂). On what' factors does the
(i) slope and
(ii) intercept of the lines depend ?

Draw a plot showing the variation of potoelectric current with collector plate potential for two different frequencies, v₁ > v₂ of incident radiation having the same intensity. In which case will the stopping potential be hgiher ? Justify your answer.