Taking Rydberg’s constant ${\mathrm{R}}_{\mathrm{H}}=1.097\times {10}^7 \mathrm{m}$ first and second wavelength of Balmer series in hydrogen spectrum is

(1) 2000 Å, 3000 Å                 

(2) 1575 Å, 2960 Å

(3) 6529 Å, 4280 Å                 

(4) 6552 Å, 4863 Å

The kinetic energy of electron in the first Bohr orbit of the hydrogen atom is 

(1) – 6.5 eV               

(2) – 27.2 eV

(3) 13.6 eV               

(4) – 13.6 eV

In Bohr’s model of hydrogen atom, which of the following pairs of quantities are quantized 

(1) Energy and linear momentum

(2) Linear and angular momentum

(3) Energy and angular momentum

(4) None of the above

The energy of the highest energy photon of Balmer series of hydrogen spectrum is close to
(1) 13.6 eV             

(2) 3.4 eV

(3) 1.5 eV               

(4) 0.85 eV

Which one of the relation is correct between time period and number of orbits while an electron is revolving in a orbit

(1) ${\mathrm{n}}^2$             

(2) $\frac{1}{{\mathrm{n}}^2}$

(3) ${\mathrm{n}}^3$             

(4) $\frac{1}{\mathrm{n}}$

An electron changes its position from orbit n = 4 to the orbit n = 2 of an atom. The wavelength of the emitted radiation’s is (R = Rydberg’s constant)

(1) $\frac{16}{\mathrm{R}}$             

(2) $\frac{16}{3\mathrm{R}}$

(3) $\frac{16}{5\mathrm{R}}$             

(4) $\frac{16}{7\mathrm{R}}$

If the energy of a hydrogen atom in nth orbit is ${\mathrm{E}}_{\mathrm{n}}$, then energy in the nth orbit of a singly ionized helium atom will be 

(1) 4${\mathrm{E}}_{\mathrm{n}}$             

(2) ${\mathrm{E}}_{\mathrm{n}}$/4

(3) 2${\mathrm{E}}_{\mathrm{n}}$             

(4) ${\mathrm{E}}_{\mathrm{n}}$/2

The ground state energy of hydrogen atom is – 13.6 eV. What is the potential energy of the electron in this state

1. 0 eV                       

2. – 27.2 eV

3. 1 eV                       

4. 2 eV

As the electron in Bohr orbit of Hydrogen atom passes from state n = 2 to n = 1 , the kinetic energy K and potential energy U change as 

(1) K two-fold, U four-fold

(2) K four-fold, U two-fold

(3) K four-fold, U also four-fold

(4) K two-fold, U also two-fold

The magnetic moment $\left(\mathrm{\mu }\right)$ of a revolving electron around the nucleus varies with principal quantum number n as

(1) $\mathrm{\mu }\propto \mathrm{n}$            

(2) $\mathrm{\mu }\propto 1/\mathrm{n}$

(3) $\mathrm{\mu }\propto {\mathrm{n}}^2$           

(4) $\mathrm{\mu }\propto 1/{\mathrm{n}}^2$