Question

The work functions of two photosensitive metal surfaces A and B are in the ratio 2:3. If x and y are the slopes of the graphs drawn between the stopping potential and frequency of incident light for the surfaces A and B respectively, then \(x : y\) is:

• A. 1:1
• B. 2:3
• C. 4:9
• D. 2:5

Hint:

In photoelectric effect experiments, the slope of the stopping potential vs. frequency graph is a constant value given by \( \frac{h}{e} \).

Answer 1

The Correct Option is A

The slopes \( x \) and \( y \) represent the Planck constant \( h \) divided by the charge \( e \) in the photoelectric equation \( V = \frac{h}{e}(f - f_0) \). Since the slopes depend on universal constants \( h \) and \( e \), they are the same for any material, leading to a ratio \( x : y = 1:1 \).