The de-Broglie wavelength associated with a hydrogen molecule moving with a thermal velocity of 3 km/s will be
(1) 1 Å                     

(2) 0.66 Å

(3) 6.6 Å                 

(4) 66 Å

When the momentum of a proton is changed by an amount ${\mathrm{P}}_0$, the corresponding change in the de-Broglie wavelength is found to be 0.25%. Then, the original momentum of the proton was 
(a) ${\mathrm{P}}_0$                   (b) 100  ${\mathrm{P}}_0$
(c) 400 ${\mathrm{P}}_0$             (d) 4 ${\mathrm{P}}_0$

The de-Broglie wavelength of a neutron at 27 $°\mathrm{C}$ is $\mathrm{\lambda }$. What will be its wavelength at 927 $°\mathrm{C}$
(a) $\mathrm{\lambda }$ / 2                        (b) $\mathrm{\lambda }$ / 3
(c) $\mathrm{\lambda }$ / 4                        (d) $\mathrm{\lambda }$ / 9

An electron and proton have the same de-Broglie wavelength. Then the kinetic energy of the electron is

(1) Zero
(2) Infinity
(3) Equal to the kinetic energy of the proton
(4) Greater than the kinetic energy of the proton

For moving ball of cricket, the correct statement about de-Broglie wavelength is

(1) It is not applicable for such big particle

(2) $\frac{\mathrm{h}}{\sqrt{2\mathrm{mE}}}$

(3) $\sqrt{\frac{\mathrm{h}}{2\mathrm{mE}}}$

(4) $\frac{\mathrm{h}}{2\mathrm{mE}}$

The kinetic energy of an electron with de-Broglie wavelength of 0.3 nanometer is 

(1) 0.168 eV           

(2) 16.8 eV

(3) 1.68 eV             

(4) 2.5 eV

A proton and an $\mathrm{\alpha }$-particle are accelerated through a potential difference of 100 V. The ratio of the wavelength associated with the proton to that associated with an $\mathrm{\alpha }$-particle is 

(1) $\sqrt{2}:1$              

(2) 2:1

(3) $2\sqrt{2}:1$             

(4) $\frac{1}{2\sqrt{2}}:1$

The wavelength of de-Broglie wave is 2$\mathrm{\mu }$m, then its momentum is (h = $6.63\times {10}^{-34}$ J-s) 
(a) $3.315\times {10}^{-28}$ kg-m/s            (b) $1.66\times {10}^{-28}$ kg-m/s
(c) $4.97\times {10}^{-28}$ kg-m/s              (d) $9.9\times {10}^{-28}$ kg-m/s

If the kinetic energy of a free electron doubles, its de-Broglie wavelength changes by the factor 
(1) $\frac{1}{\sqrt{2}}$             

(2) $\sqrt{2}$

(3) $\frac{1}{2}$                

(4) 2

The energy that should be added to an electron to reduce its de Broglie wavelength from one nm to 0.5 nm is

(a) Four times the initial energy

(b) Equal to the initial energy

(c) Twice the initial energy

(d) Thrice the initial energy