A radiation of energy $'E'$ falls normally on a perfectly reflecting surface. The momentum transferred to the surface is $( C =$ Velocity of light $)$
An AIR station is broadcasting the waves of wavelength $300$ metres. If the radiating power of the transmitter is $10 kW$, then the number of photons radiated per second is
A radio transmitter radiates $1 kW$ power at a wavelength $198.6 $ metres. How many photons does it emit per second
One day on a spacecraft corresponds to $2$ days on the earth. The speed of the spacecraft relative to the earth is
A Laser light of wavelength $660\,nm$ is used to weld Retina detachment. If a Laser pulse of width $60\, ms$ and power $0.5\, kW$ is used the approximate number of photons in the pulse are : [Take Planck's constant $h\, = 6.62\times10^{- 34}\, Js$]