Wavelength of $H^{+}$ ion with kinetic energy $1.65 \ eV$ is (mass of proton $= 1.6726 \times 10^{-27} \ kg$) (in $nm$)

Number of waves formed by a Bohr electron in one complete revolution in its third orbit is

If $a_0$ is the radius of the first Bohr's orbit of the $H$-atom, the de-Broglie wavelength of an electron revolving in the second Bohr's orbit will be: (in $\pi a_0$)

If the de Broglie wavelength of an electron is $728.14 \ nm$,its kinetic energy in $J$ is: (mass of electron $= 9.1 \times 10^{-31} \ kg$; $h = 6.626 \times 10^{-34} \ J \ s$)

Find the $\%$ difference (approximate) in de Broglie wavelength if the temperature of a gas becomes double.

According to de Broglie,matter should exhibit dual behaviour,that is both particle and wave-like properties. However,a cricket ball of mass $100 \ g$ does not move like a wave when it is thrown by a bowler at a speed of $100 \ km/h$. Calculate the wavelength of the ball and explain why it does not show wave nature.