The de Broglie equation applies to:

Which one of the following explains light both as a stream of particles and as wave motion?

The de Broglie wavelength of an electron in the $4^{th}$ Bohr orbit is (in $\pi a_{0}$)

What should be the momentum (in $g \ cm / s$) of a particle if its de Broglie wavelength is $1 \ \mathring{A}$ and the value of $h$ is $6.6252 \times 10^{-27} \ erg \ s$?

The de Broglie wavelength is given as $1 \, \mathring{A}$ and the value of $h$ is $6.6252 \times 10^{-27} \, \text{erg} \cdot \text{s}$. What will be the momentum of the particle (in $\text{g} \cdot \text{cm/s}$)?

What will be the de Broglie wavelength associated with a charged proton in $\mathring{A}$? ($V =$ potential difference)