Question

In a photoelectric graph of stopping potential vs frequency, straight line makes angle \( \theta \) with Y-axis. Then \( \tan \theta = \):

• A. \( \frac{h}{e} \)
• B. \( \frac{e}{h} \)
• C. \( \sqrt{\frac{h}{e}} \)
• D. \( \sqrt{\frac{e}{h}} \)

Hint:

Slope of \( V \) vs \( f \) graph in photoelectric effect gives \( \frac{h}{e} \).

Answer 1

The Correct Option is A

Einstein’s equation: \( eV = hf - \phi \Rightarrow V = \frac{h}{e}f - \frac{\phi}{e} \)
So slope of graph \( V \) vs \( f \) = \( \frac{h}{e} \Rightarrow \tan \theta = \frac{h}{e} \)