Question

The frequency of incident light falling on a photosensitive metal plate is doubled, the kinetic energy of the emitted photoelectrons is:

• A. double the earlier value
• B. quadrupled
• C. halved
• D. zero

Hint:

The kinetic energy of photoelectrons increases linearly with the frequency of incident light.

Answer 1

The Correct Option is A

Step 1: Use Einstein's photoelectric equation.
The kinetic energy of the emitted electrons is given by: \[ K.E. = h \nu - \phi \] where \( h \) is Planck’s constant, \( \nu \) is the frequency of light, and \( \phi \) is the work function of the material.
Step 2: Explanation.
Doubling the frequency of incident light doubles the kinetic energy of the emitted electrons, as \( K.E. \) is directly proportional to the frequency of the incident light.
Final Answer: \[ \boxed{\text{double the earlier value}} \]