The work function for a certain metal is 4.2eV. Will this metal give photoelectric emission for incident radiation of wavelength 330 nm? Use, \(h=6.6\times { 10 }^{ -34 }Js\)

2

(a)

Ultraviolet light is incident on two photosensitive materials having work function \({ \phi }_{ 1 }\ and\ { \phi }_{ 2 }.\) In which case will the K.E. of the emitted electrons be greater? Why? 

2

(a)

If the wavelength of an electromagnetic radiation is doubled, what will happen to (i) the energy of photons and (ii) the momentum of a photon?

2

(a)

Why is the wave nature of matter not more apparent to our daily observations?

2

(a)

A particle with rest mass is \({ m }_{ 0 }\) moving with velocity c. What is the de-Broglie wavelength associated with it?

2

(a)

An electron and a proton have the same de-Broglie wavelength. Which one these have higher kinetic energy? Which one is moving faster?

2

(a)

(i) For what kinetic energy of a neutron will associated de Broglie wavelength be 1.40 x 10^-10m?
(ii) Also find the de-Broglie wavelength of a neutron in thermal equilibrium with matter,having an average kinetic energy of (3/2) kT and temperature is 300 K.

2

(a)

A proton and α particle have the same de-Broglie wavelength. Determine the ratio of
(i) their accelerating potentials
(ii) their speeds

2

(a)

Write Einstein's photoelectric equation.Explain the terms of stopping potential.

2

(a)

An electron is revolving around the nucleus with a constant speed of 2.2 x 10⁸ m/s. Find the de Broglie wavelength associated with it.

2

(a)

An \(\alpha \)-particle and a proton are accelerated from rest by the same potential. Find the ratio of their de-broglie wavelengths.

2

(a)

Find the ratio of the de Broglie wavelengths, associated with
(i) protons, accelerated through a potential of 128 V, and
(ii) \(\alpha \)-particles, accelerated through a potential of 64 V.

2

(a)