Question

In experiment of photoelectric effect, the stopping potential for incident yellow light of wavelength \(5890\text{\AA}\) is 4 V. If the yellow light is replaced by blue light of wavelength \(4000\text{\AA}\), the stopping potential is

• A. zero volt
• B. more than 4 V
• C. 4 V
• D. less than 4 V

Hint:

Shorter wavelength always means higher stopping potential in photoelectric effect.

Answer 1

The Correct Option is B

Step 1: Photoelectric equation.
\[ eV_0 = h\nu - \phi \]
Step 2: Relation between frequency and wavelength.
\[ \nu = \frac{c}{\lambda} \]
Step 3: Comparison of wavelengths.
Blue light has shorter wavelength than yellow light, hence higher frequency and higher photon energy.
Step 4: Effect on stopping potential.
Higher photon energy increases maximum kinetic energy of photoelectrons, therefore stopping potential increases.
Step 5: Conclusion.
The stopping potential will be more than 4 V.