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An electron with mass ‘m’ with an initial velocity (t = 0) v G = v 0 i ˆ (v 0 > 0) enters a magnetic field B G = B 0 j ˆ . If the initial de- Broglie wavelength at t = 0 is λ 0 then its value after time 'f' would be :

1. 2 2 2 0 2 0 m t B e 1 − λ
2. 2 2 2 0 2 0 m t B e 1 + λ
3. λ 0 2 2 2 0 2 m t B e 1 +
4. λ 0

Correct answer: λ 0

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