NEET 2016 Phase 1 · PhysicsElectron-photonPrevious Year Question
An electron of mass m and a photon have the same energy E. The ratio of the de Broglie wavelengths associated with them is (c being the velocity of light):
Answer: (A) (1/c)·(E/2m)^(1/2). Answer: (a) (1/c)·(E/2m)^(1/2) Solution: Electron: λₑ = h/√(2mE).
- A.(1/c)·(E/2m)^(1/2)✓
- B.(E/2m)^(1/2)
- C.c·(2mE)^(1/2)
- D.(1/c)·(2m/E)^(1/2)
Correct Answer
(A) (1/c)·(E/2m)^(1/2)
Solution & Explanation
Answer: (a) (1/c)·(E/2m)^(1/2) Solution: Electron: λₑ = h/√(2mE). Photon: λ_ph = hc/E. λₑ/λ_ph = (h/√(2mE))·(E/hc) = (1/c)·√(E/2m).
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