In an electron gun, the electrons are accelerated by the potential V. If e is the charge and m is the mass of an electron, then the maximum velocity of these electrons will be

(1) $\frac{2\mathrm{eV}}{\mathrm{m}}$                   

(2) $\sqrt{\frac{2\mathrm{eV}}{\mathrm{m}}}$

(3) $\sqrt{\frac{2\mathrm{m}}{\mathrm{eV}}}$                 

(4) $\frac{{\mathrm{V}}^2}{2\mathrm{em}}$

The idea of matter waves was given by
(1) Davisson and Germer                 

(2) de-Broglie

(3) Einstein                                     

(4) Planck

Waves are associated with matter only:

The de-Broglie wavelength associated with the particle of mass m moving with velocity v is

(1) h/mv                 

(2) mv/h 

(3) mh/v                 

(4) m/hv

A photon, an electron, and a uranium nucleus all have the same wavelength. The one with the most energy: 

(1) Is the photon

(2) Is the electron

(3) Is the uranium nucleus

(4) Depends upon the wavelength and the properties of the particle

When the kinetic energy of an electron is increased, the wavelength of the associated wave will
(1) Increase

(2) Decrease

(3) Wavelength does not depend on the kinetic energy

(4) None of the above

If the de-Broglie wavelengths for a proton and an alpha-particle are equal, then the ratio of their velocities will be:
1. \(4:1\)
2. \(2:1\)
3. \(1:2\)
4. \(1:4\)

The de-Broglie wavelength $\mathrm{\lambda }$ associated with an electron having kinetic energy E is given by the expression

(1) $\frac{\mathrm{h}}{\sqrt{2\mathrm{mE}}}$                           

(2) $\frac{2\mathrm{h}}{\mathrm{mE}}$

(3) 2mhE                               

(4) $\frac{2\sqrt{2\mathrm{mE}}}{\mathrm{h}}$

Dual nature of radiation is shown by:

(1) Diffraction and reflection

(2) Refraction and diffraction

(3) Photoelectric effect alone

(4) Photoelectric effect and diffraction