In a Rutherford scattering experiment when a projectile of charge Z₁ and mass M₁ approaches a target nucleus of charge Z₂ and mass M₂, the distance of closest approach is r_o.The energy of the projectile is 

• directly proportional to M₁ x M₂

• directly proportional to Z₁Z₂

• inversely proportional to Z₁

• inversely proportional to Z₁

The ionisation energy of the electron in the hydrogen atom in its ground state is 13.6 eV. The atoms are excited to higher energy levels to emit radiations of 6 wavelengths. Maximum wavelength of emitted radiation corresponds to the transition between

• n = 3 to n =2 states

• n = 3 to n = 1 states

• n = 2 to n = 1 states

• n = 2 to n = 1 states

The total energy of an electron in the ground state of a hydrogen atom is -13.6 eV. The kinetic energy of an electron in the first excited state is: 

• 3.4 eV

• 6.8 eV

• 13.6 eV

• 13.6 eV

Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be

• two 

• three

• four

• four

The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

• 2

• 1

• 4

• 4

The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is

• 1:1

• 1:-1

• 1:-2

• 2:-1

An electron of mass m with an initial velocity $\overrightarrow{V} = V_o\hat{i} (V_o>0)$ enters an electric field $\overrightarrow{E} = - E_o \hat{i}$ (E₀ constant >0) at t = 0. if λ₀ is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is

• $\frac{{\lambda }_0}{\left(1+{\displaystyle \frac{e{E}_0}{m{V}_0}}t\right)}$

• ${\lambda }_o\left(1 + \frac{e{E}_0}{m{V}_0}t\right)$

• ${\lambda }_0$

• ${\lambda }_{0}t$

The potential of an atom is given by V = V₀loge(r/r₀) where r₀ is a constant and r is the radius of the orbit. Assuming Bohr's model to be applicable, which variation or r_n with n is possible (n being a principal quantum number)?

• ${\mathrm{r}}_{\mathrm{n}} \propto \mathrm{n}$

• ${\mathrm{r}}_{\mathrm{n}} \propto \frac{1}{\mathrm{n}}$

• ${\mathrm{r}}_{\mathrm{n}} \propto {\mathrm{n}}^2$

• ${\mathrm{r}}_{\mathrm{n}} \propto \frac{1}{{\mathrm{n}}^2}$

The electric potential at the surface of an atomic nucleus (Z = 50) of radius 9.0$\times {10}^{-15}$m is

• 8$\times {10}^6 \mathrm{V}$

• 80V

• $9\times {10}^{5 }\mathrm{V}$

• 9V

120.

The radius of electron second stationary orbit in Bohr's atom is R. The radius of third orbit will be

• 2.25R

• 3R

• R/3

• 9R