The wavelengths of electron waves in two orbits are in the ratio $3: 5$. The ratio of the kinetic energy of the electrons will be:

If the wavelength of a photon is $2.2 \times 10^{-11} \ m$ and $h = 6.6 \times 10^{-34} \ J \ s$,then the momentum of the photon is:

The de-Broglie wavelength of a tennis ball of mass $60 \, g$ moving with a velocity of $10 \, m/s$ is approximately

The velocities of two particles $A$ and $B$ are $0.05 \ ms^{-1}$ and $0.02 \ ms^{-1}$ respectively. The mass of $B$ is five times the mass of $A$. The ratio of their de-Broglie's wavelength is

The kinetic energy of an electron is $4.55 \times 10^{-25} \ J$ and its mass is $9.1 \times 10^{-31} \ kg$. Calculate the velocity,momentum,and wavelength of the electron.

When an electron in a hydrogen atom jumps from the third excited state to the ground state,the de-Broglie wavelength associated with the electron becomes