Which of the following statements about the properties of X-rays is incorrect?

1.  X-rays can ionize gases.

2.  X-rays produce fluorescence in zinc sulphide (ZnS).

3.  X-rays are deflected by electric and magnetic fields.

4.  X-rays have shorter wavelengths than ultraviolet rays.

Which of the following terms describes the characteristic spectrum produced by the atoms of an element?

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.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right)<mspace\; width="1em"></mspace>\left(\mathrm{n}+1\right)}{{\mathrm{n}}^2}<mspace\; width="1em"></mspace>{\mathrm{cm}}^{-1}$

2.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right)<mspace\; width="1em"></mspace>\left(\mathrm{n}+2\right)}{4{\mathrm{n}}^2}<mspace\; width="1em"></mspace>{\mathrm{cm}}^{-1}$

3.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-2\right)<mspace\; width="1em"></mspace>\left(\mathrm{n}+2\right)}{{\mathrm{n}}^2}<mspace\; width="1em"></mspace>{\mathrm{cm}}^{-1}$

4.  $\overline{\mathrm{v}}=\frac{\mathrm{R}\left(\mathrm{n}-1\right)<mspace\; width="1em"></mspace>\left(\mathrm{n}+1\right)}{4{\mathrm{n}}^2}<mspace\; width="1em"></mspace>{\mathrm{cm}}^{-1}$

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