Question

the threshold frequency for a certain metal for Photoelectric effect is 1.7 into 10 raise to 15 hertz when light of frequency 2.2 into 10 raise to 15 hertz is incident on the metal surface, the kinetic energy of the emitted photoelectrons is 3.3 into 10 raise to minus 19 joule full stop calculate Planck's Constant

Answer 1

Energy in light = plancks constant * frequency of light

let plancks constant be h
Kinetic energy = Energy given - Energy used in coming out of plate

3.3 * 10^-19 = h*(2.2-1.7)*10^15
(3.3*10^-34)/0.5 = h

h = 6.6 * 10^ -34 J-s