The work function of a metal surface is \(\phi = 1.5\) eV. If a light of wavelength \(5000~\mathring{A}\) falls on it, then the maximum K.E of the ejected electron will be:

1.	\(1.2\) eV	2.	\(0.98\) eV
3.	\(0.45\) eV	4.	\(0\) eV

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:

1.		2.
3.		4.

The current conduction in a discharge tube is due to:
1.  electrons only
2.  +ve ions and –ve ions
3.  –ve ions and electrons
4.  +ve ions and electrons

If a light of amplitude A and wavelength λ is incident on a metallic surface, then the saturation current flow is proportional to (assume cut-off wavelength = ${\lambda }_0$):

1. $A^2,$ $if$ $\lambda$ $>$ ${\lambda }_0$

2. $A^2,$ $if$ $\lambda$ $<$ ${\lambda }_0$

3. $A,$ $if$ $\lambda$ $>$ ${\lambda }_0$

4. $A,$ $if$ $\lambda$ $<$ ${\lambda }_0$

The total energy of an electron is \(3.555~\text{MeV}\). Its kinetic energy will be:
1.  \(3.545~\text{MeV}\)
2.  \(3.045~\text{MeV}\)
3.  \(3.5~\text{MeV}\)
4.  none of the above

The value of Planck's constant is:
1. \(6.63\times 10^{-34}~\text{J/s}\)
2. \(6.63\times 10^{-34}~\text{kg-}\text{m}^2\text{/s}\)
3. \(6.63\times 10^{-34}~\text{kg-}\text{m}^2\)
4. \(6.63\times 10^{-34}~\text{J-s}^2\)

If particles are moving with the same velocity, then the de-Broglie wavelength is maximum for:
1. proton
2. \(\alpha\text-\)particle
3. neutron
4. \(\beta\text-\)particle