Question

The potential difference between two parallel plates is ${10}^4$ volt. If the plates are separated by $0.5cm$, the force on an electron between the plates is :

• A. $2\times {10}^{4}N$
• B. $3.2\times {10}^{-13}N$
• C. $20N$
• D. $32\times {10}^{12}N$

Answer 1

The correct option is B $3.2\times {10}^{-13}N$

We know $E=\frac{V}{L}$
$E=\frac{{10}^4}{0.5\times {10}^{-2}}$

$E=2\times {10}^6$
|force on an electron| $=|qE|$
$=2\times {10}^6\times 1.6\times {10}^{-19}$
$=3.2\times {10}^{-13}N$