The energy of a photon of wavelength $\lambda $ is given by

Which of one is correct

Dual nature of radiation is shown by

A point source is emitting sound waves of intensity $16 \times 10^{-8} \mathrm{Wm}^{-2}$ at the origin. The difference in intensity (magnitude only) at two points located at a distances of $2 \mathrm{~m}$ and $4 \mathrm{~m}$ from the origin respectively will be______ $\times 10^{-8} \mathrm{Wm}^{-2}$

The energy of a photon is $E = hv$ and the momentum of photon $p = \frac{h}{\lambda }$, then the velocity of photon will be