If h is Planck's constant, find the momentum of a wavelength 0.4\(\mathring { A } \)

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?

(i) Write the important properties of photons which are used to establish Einstein's photoelectric equation.
(ii) Use this equation to explain the concept of 
(a) threshold frequency and 
(b) stopping potential.

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 thr Einstein's theory.

A proton and an electron have same de-Broglie Wavelength. Which of them moves fast and which possesses more kinetic energy? Justify your answer.