Question

The linear momentum of an electron, initially at rest, accelerated through a potential difference of 100 V is (in kg $m{s}^{-1}$)

• A. $2.25\times {10}^7$
• B. $5.4\times {10}^{-24}$
• C. $5.4\times {10}^7$
• D. $2.85\times {10}^{-24}$

Answer 1

The correct option is B $5.4\times {10}^{-24}$

Here $\frac{p^2}{2m}=eV\Rightarrow p=\sqrt{2meV}=\sqrt{2\times 9.1\times {10}^{-31}\times 1.6\times {10}^{-19}\times 100}=5.4\times {10}^{-24}kgm{s}^{-1}$