If the radius of the first orbit of hydrogen atom is $a_0$, then de Broglie's wavelength of electron in $3^{rd}$ orbit is (in $\pi a_0$)

The wavelength associated with the electron moving in the first orbit of hydrogen atom with velocity $2.2 \times 10^6 \ ms^{-1}$ (in $nm$) is $\left(m_e=9.0 \times 10^{-31} \ kg, h=6.6 \times 10^{-34} \ Js\right)$

For which of the following does the mathematical expression $\lambda = \frac{h}{p}$ stand?

If the kinetic energy of an electron of mass $9.0 \times 10^{-31} \ kg$ is $8.0 \times 10^{-25} \ J$,the wavelength of this electron in $nm$ is

Dual nature of particles was proposed by

The de Broglie wavelength of an electron travelling with $20 \%$ of velocity of light is
$(h = 6.626 \times 10^{-34} \ J \ s; m_{e} = 9.1 \times 10^{-31} \ kg)$