"Red light with a wavelength of 660 {~nm} from a 3.0 {~mW} diode laser shines on a solar cell.
(a) How many photons per second are emitted by the laser? (1 {~W}=1 {~J} / {s})
(b) How much current (in amperes) flows in the circuit of the solar cell if all the photons are absorbed by the cell and each photon produces one electron?"
a) 2.5× 10^{15} photons/s, 3.75× 10^{-9} A
b) 5.0× 10^{15} photons/s, 7.5× 10^{-9} A
c) 3.0× 10^{15} photons/s, 4.5× 10^{-9} A
d) 4.0× 10^{15} photons/s, 6.0× 10^{-9} A