# Find the energy of a photon in electron volt of microwaves having wavelength $3mm.(1\: eV = 1.6 \times 10^{-19}J)$
$(a) 41.4 \times 10^{-2}\; eV\quad (b) 4.14 \times 10^{-4}\; eV$
$(c) 4.14 \times 10^{-2}\; eV\quad (b) 41.4 \times 10^{-4}\; eV$