MHT CET202523 Apr 2025Morning ShiftPhysicsDual Nature of MatterActual
The energy that should be added to an electron to reduce its de-Broglie wavelength from to 2 is n times the initial energy. The value of ' n ' is
Options
- A4
- B3
- C2
- D1
Correct answer
B. 3
Step-by-step solution
The de-Broglie wavelength ₁ = corresponds to kinetic energy E₁ = h^2 2m ^2 derived from = h p and E = p^2 2m . When the wavelength decreases to ₂ = 2 , the new kinetic energy becomes E₂ = h^2 2m( /2)^2 = 4E₁ . The required energy addition is E = E₂ - E₁ = 3E₁ , yielding n = 3 since E = nE₁ . Final answer: 3