A proton is projected in a uniform magnetic field of induction B in a direction perpendicular to the field. Mass of proton is m, charge is e. If radius of its trajectory is r, what is the de Broglie wavelength of the proton? Given $\mathrm{B}=1\mathrm{T}, \mathrm{r}=1\mathrm{m}, \mathrm{m}=1.67 \mathrm{x} {10}^{-27} \mathrm{kg}$