JEE Main20257 Apr 2025Evening ShiftPhysicsDual Nature of MatterActual
A photo-emissive substance is illuminated with a radiation of wavelength _i so that it releases electrons with de-Broglie wavelength _e . The longest wavelength of radiation that can emit photoelectron is ₀ . Expression for de-Broglie wavelength is given by : ( m : mass of the electron, h : Planck's constant and c : speed of light)
Options
- A_ e = h 2 mc ( 1 _ i - 1 ₀ )
- B_ e = h ₀ 2 mc
- C_ e = h 2 mc ( 1 _ i - 1 ₀ )
- D_ e = h _ i 2 mc
Correct answer
A. _ e = h 2 mc ( 1 _ i - 1 ₀ )
Step-by-step solution
aligned & K . E = E - W & _ e = h 2 mK E , E = hc _ i , W = hc ₀ & ~h ^2 2 ~m _ e ^2 = hc _ i - hc ₀ & _ e = h 2 mc ( 1 _ i - 1 ₀ ) aligned