1.5mW of 400nm light is directed at a photoelectric cell. If 0.1% of the incident photon produce photoelectrons,find the current in the cell? (Answer is 0.48microA)....PLS answer fast ........

for wavelength 400 nm , energy of each photon be E=hc/lamda

 n number of photons will have  total energy n(E) ...

power of photon beam is given so

n(E) = 1.5mW .....

n = 1.5/E           (number of photons striking per second)

0.1% photons extract electrons so

n_e(number of ejected electrons) = 0.1% of n

now photo current = nq=ne            (e is electronic charge)

put all the values & u will get ans 0.48microA current