### NEET Solved Paper 2019 Question 10

##### Question: An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is, (nearly) $ (m _{e}=9\times 10^{31}kg) $ : [NEET 5-5-2019]

#### Options:

A) $ 12.2\times 10^{14}m $

B) 12.2 nm

C) $ 12.2\times 10^{13}m $

D) $ 12.2\times 10^{12}m $

## Show Answer

#### Answer:

Correct Answer: D

#### Solution:

$ \lambda =\frac{12.27}{\sqrt{V}}\overset{o}{\mathop{A}},=\frac{12.27}{\sqrt{10,000}}\overset{o}{\mathop{A}}, $

$ =12.27\times 10^{2}\overset{o}{\mathop{A}}, $

$ =12.27\times 10^{12}m $