The energy of an electron moving in n^th Bohr's orbit of an element is given by ${\mathrm{E}}_{\mathrm{n}}=\frac{-13.6}{{\mathrm{n}}^2}{\mathrm{Z}}^2$ eV/atom (Z=atomic number). The graph of $\mathrm{E} \mathrm{vs}. {\mathrm{Z}}^2$ (keeping "n" constant) will be:

1.		2.
3.		4.

The spectrum produced from an element is:

1.  atomic spectrum

2.  line spectrum

3.  absorption spectrum

4.  any one of the above

Which of the following expressions represents the spectrum of Balmer series (If n is the principal quantum number of higher energy level) in Hydrogen atom?

1.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right) \left(\mathrm{n}+1\right)}{{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

2.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right) \left(\mathrm{n}+2\right)}{4{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

3.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right) \left(\mathrm{n}+2\right)}{{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

4.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right) \left(\mathrm{n}+1\right)}{4{\mathrm{n}}^2} {\mathrm{cm}}^{-1}$

The H-spectrum show:

1.  Heisenberg's uncertainty principle

2.  Diffraction

3.  Polarization

4.  Presence of quantized energy level

In photoelectric effect, the kinetic energy of photoelectrons increases linearly with the:

1. Wavelength of incident light.

2. Frequency of incident light.

3. Velocity of incident light.

4. Atomic mass of an element.

Slope of ${\mathrm{V}}_0$ vs v curve is (where ${\mathrm{V}}_0$=stopping potential, v=subjected frequency)

1.  $\mathrm{e}$

2.  $\frac{\mathrm{h}}{\mathrm{e}}$

3.  $\mathrm{\varphi }$

4.  $\mathrm{h}$

What is the nature of the graph between the kinetic energy of photoelectrons ejected and the frequency of the incident radiation, based on Einstein's photoelectric equation?
 

1.
2.
3.
4.

The photoelectric emission from a surface starts only when the light incident upon the surface has a certain minimum:

If ${\mathrm{\lambda }}_0$ and $\mathrm{\lambda }$ be the threshold wavelength and the wavelength of incident light, the velocity of photo-electrons ejected from the metal surface is:

1.  $\sqrt{\frac{2\mathrm{h}}{\mathrm{m}}\left({\mathrm{\lambda }}_0-\mathrm{\lambda }\right)}$

2.  $\sqrt{\frac{2\mathrm{hc}}{\mathrm{m}}\left({\mathrm{\lambda }}_0-\mathrm{\lambda }\right)}$

3.  $\sqrt{\frac{2\mathrm{hc}}{\mathrm{m}}\left(\frac{{\mathrm{\lambda }}_0-\mathrm{\lambda }}{{\mathrm{\lambda \lambda }}_0}\right)}$

4.  $\sqrt{\frac{2\mathrm{h}}{\mathrm{m}}\left(\frac{1}{{\mathrm{\lambda }}_0}-\frac{1}{\lambda }\right)}$

The ratio of slopes of ${\mathrm{K}}_{\max } \mathrm{vs}. \mathrm{v} \mathrm{and} {\mathrm{V}}_0 \mathrm{vs}. \mathrm{v}$ curves in photoelectric effect gives -

(v=frequency, ${\mathrm{K}}_{\max }$=maximum kinetic energy, ${\mathrm{V}}_0$ stopping potential):

1.  Charge of electron

2.  Planck's constant

3.  Work function

4.  The ratio of Planck's constant of electronic charge