NEET 2020 · PhysicsElectron λPrevious Year Question
An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is 1.227 × 10⁻² nm, the potential difference is:
Answer: (B) 10⁴ V. Answer: (b) 10⁴ V Solution: λ = 12.27/√V Å = (12.27/√V) × 10⁻¹⁰ m.
- A.10³ V
- B.10⁴ V✓
- C.10 V
- D.10² V
Correct Answer
(B) 10⁴ V
Solution & Explanation
Answer: (b) 10⁴ V Solution: λ = 12.27/√V Å = (12.27/√V) × 10⁻¹⁰ m. Given λ = 1.227 × 10⁻² nm = 0.1227 × 10⁻¹⁰ m = 12.27/√V × 10⁻¹² m... ⇒ √V = 100 ⇒ V = 10⁴ V.
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