Modern Physics 2 Question 32
31. In a photoelectric experiment set-up, photons of energy $5 eV$ falls on the cathode having work function $3 eV$. (a) If the saturation current is $i _A=4 \mu A$ for intensity $10^{-5} W / m^{2}$, then plot a graph between anode potential and current. (b) Also, draw a graph for intensity of incident radiation $2 \times 10^{-5} W / m^{2}$.
$(2003,2 M)$
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Solution:
- Maximum kinetic energy of the photoelectrons would be
Therefore, the stopping potential is $2 V$. Saturation current depends on the intensity of light incident. When the intensity is doubled the saturation current will also become two fold. The corresponding graphs are shown in above figure.
