Question

An electron is accelerated under a potential difference of 182 V. The maximum velocity of electron will be (charge of electron is $1.6\times {10}^{-19}C$ and its mass is $9.1\times {10}^{-31}kg$)

• A. $800m{s}^{-1}$
• B. $8\times {10}^{6}m{s}^{-1}$
• C. $4\times {10}^{3}m{s}^{-1}$
• D. $4\times {10}^{6}m{s}^{-1}$

Answer 1

The correct option is B $8\times {10}^{6}m{s}^{-1}$

$\frac{1}{2}m{v}^2=eV\Rightarrow v=\sqrt{\frac{2\times 1.6\times {10}^{-19}\times 182}{9.1\times {10}^{-31}}}=8\times {10}^{6}m{s}^{-1}$