The work function of a surface of a photosensitive material is . The wavelength of the incident radiation for which the stopping potential is lies in the:
Infrared region
X-ray region
Ultraviolet region
Visible region
Ultraviolet region
Explanation for the correct option
Step 1: Given
Work function is
Stopping potential
Step 2: Formula used
We have to use work function formula . Total energy of photon hitting a metal surface is equal to sum of work function of metal and energy of ejected electron.
, where is Planck's constant, work function, speed of light, wavelength,
Step 3: Solution for wavelenth
This wavelength lies in the ultraviolet region
Explanation for the incorrect option
Option (A)
The wavelength in the infrared region ranges from , since the wavelength is only so it is not in the infrared region.
Option (B)
The wavelength in the X-ray region ranges from , since the wavelength is only so it is not in the X-ray region .
Option (D)
The wavelength in the Visible region ranges from , since the wavelength is only so it is not in the Visible region
Hence, option C is correct.