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 $h\, = 6.62\times10^{- 34}\, Js$]
$10^{20}$
$10^{18}$
$10^{22}$
$10^{19}$
What is photoelectron ?
The value of Planck's constant is
According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is
A photon collides with a stationary hydrogen atom in ground state inelastically. Energy of the colliding photon is $10.2 \ eV$. After a time interval of the order of micro second another photon collides with same hydrogen atom inelastically with an energy of $15 \ eV$. What will be observed by the detector
When an inert gas is filled in the place vacuum in a photo cell, then