A photoelectric effect experiment is performed with tungsten. The work function for tungsten is 4.5 eV.
(a) If ultraviolet light of wavelength 0.20 μ m is incident on the tungsten, calculate the stopping potential.
(b) If the stopping potential is turned off (i.e., the cathode and anode are at the same voltage), the 0.20- μ m incident light produces a photocurrent of 3.7 μ A. What is the photocurrent if the incident light has wavelength 400 nm and the same intensity as before?