question_answer

de-Broglie wavelength of an electron accelerated by a voltage of 50 V is close to [JEE ONLINE 10-04-2015]

\[(|e|=1.6\times {{10}^{-19}}C,\]\[{{m}_{e}}=9.1\times {{10}^{-31}}kg,\]                          \[h=6.6\times {{10}^{-34}}Js)\]

A) \[0.5{\AA}\]

B) \[1.7{\AA}\]

C) \[2.4{\AA}\]

D) \[1.2{\AA}\]

Correct Answer: B

Solution :

[b] momentum  and