Write any three experimental observations of photoelectric effect

Explanation

`E=hv_(0)+(1)/(2)mv_("max")^(2)`
or `hv=hv_(0)+(1)/(2)mv_("max")^(2)`
Explanation : (i) Photoelectric effect is instantaneous Einstein treated the collision between photon and electron as elastic collision between two micro particles,
(i) If `v= v_(0)`, K.E. = 0 electron just released but K.E. = 0
(iii) `v gt v_(0)` or K.E is. + ve photoelectric emmumision is possible when incident radiation is greater than threshold frequency.
(iv) `v lt v_(0)`, K.E is - ve photon does not comes out from the metal.
(v) Photoelectric current intensity of incident radiation one phutun interact with one electron. As intensity of incident ray increases number of photoelectron emitted increases.