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

The velocity of a de Broglie wave is represented by which of the following expressions?

The wavelength of an electron of kinetic energy $4.50 \times 10^{-29} \ J$ is $... \times 10^{-5} \ m$. (Nearest integer) Given: mass of electron is $9 \times 10^{-31} \ kg$,$h = 6.6 \times 10^{-34} \ J \ s$.

Which of the following has the lowest de Broglie wavelength $\lambda$?

The mass of a photon with a wavelength equal to $1.54 \times 10^{-8} \ cm$ is

The $K.E.$ of an electron is $4.55 \times 10^{-25} \,J$. Calculate its $\lambda$.