99 Percentile Qs Bank for JEE MainPhysicsDual Nature of Matter
In the following arrangement, y = 1 . 0   mm , d = 0 . 24   mm and D = 1 . 2   m . The work function of the material of the emitter is 2 . 2   eV . The stopping potential V ' needed to stop the photocurrent will be:
Options
- A0 . 9   V  
- B0 . 5   V
- C0 . 4   V
- D0 . 1   V
Correct answer
A. 0 . 9   V  
Step-by-step solution
In Young's double slit experiment, Fringe Width, β = λ D d Distance between dark and bright fringe = y . So, β = 2 y λ D d = 2 y λ = 2 × 1 × 10 - 3 × 0 . 24 × 10 - 3 1 . 2   A o λ = 4000   A o Energy of photon light incident, E = 12400 λ A o E ( in   eV ) = 12400 4000 E = 3 . 1   eV To calculate the stopping potential V ' applying Einstein's photoelectric equation, E ( eV ) = W 0 + e V ' ⇒ 3 . 1   eV = 2 . 2