Question

When monochromatic light falls on a photosensitive material, the number of photoelectrons emitted per second is $n$ and their maximum kinetic energy is $K_{max}$. If the intensity of the incident light is doubled, then

• A. Both $n$ and $K_{max}$ are doubled.
  
• B. Both $n$ and $K_{max}$ are halved.
  
• C. $n$ is doubled but $K_{max}$ remains the same.
  
• D. $K_{max}$ is doubled but $n$ remains the same.
  

Answer 1

The correct option is C $n$ is doubled but $K_{max}$ remains the same.


Intensity is proportional to the number of photons released per second, and frequency decides the energy of each of the photon. Hence, as the intensity increases, the number of photons increases, and as a result, the number of electrons also increases. However, since the energy of the photon and the work function are same, $K_{max}$ remains the same.
Hence, the correct choice is (c).