The wavelength of the electron emitted by a metal sheet of work function $4 \ eV$ when photons from $EMR$ of wavelength $124 \ nm$ strike the metal plate is ........... $nm$.

The energy of separation of an electron in a Hydrogen-like atom in an excited state is $3.4 \ eV$. The de-Broglie wavelength (in $\mathring{A}$) associated with the electron is (Given: radius of the first orbit of $H$ atom is $0.53 \ \mathring{A}$)

In the ground state of a hydrogen atom,an electron absorbs $1.5$ times the minimum energy $\left(2.18 \times 10^{-18} \ J\right)$ required to escape from the atom. The wavelength of the emitted electron (in $m$) is $\left(m_e = 9 \times 10^{-31} \ kg\right)$.

The wavelength associated with a particle of mass $9.109 \times 10^{-31} \ kg$ moving with a velocity of $1.20 \times 10^5 \ m/s$ is ....... meters.

The de Broglie wavelengths of two fast moving particles $X$ and $Y$ are $1 \ nm$ and $3 \ nm$ respectively. The mass of $X$ is nine times the mass of $Y$. The ratio of kinetic energies of $X$ and $Y$ is:

An electron moves in an electric field with a kinetic energy of $2.5 \, eV$. The de Broglie wavelength associated with it is .....