The momentum of a photon is $3.3 \times 10^{-29} \ kg \ m/s$. Its frequency will be

Assertion: Mass of a moving photon varies inversely as the wavelength.
Reason: Energy of the particle $= \text{mass} \times (\text{speed of light})^2$

In an accelerator experiment on high-energy collisions of electrons with positrons,a certain event is interpreted as annihilation of an electron-positron pair of total energy $10.2 \; BeV$ into two $\gamma$-rays of equal energy. What is the wavelength associated with each $\gamma$-ray? $(1 \; BeV = 10^9 \; eV)$

Our eye can detect $5 \times 10^4$ photons per second per square meter of green light $(\lambda = 5000 \ \mathring{A})$. If the ear can detect $10^{-13} \ W/m^2$,how many times more sensitive is the eye compared to the ear?

$A$ photon,an electron,and a uranium nucleus all have the same wavelength. The one with the most energy is:

The momentum of a photon having energy $hv$ is ............