Question

Calculate the electric field strength at a distance of 3 m from a charge of 32 nC placed in air.

• A. $8N{C}^{-1}$
• B. $32N{C}^{-1}$
• C. $64N{C}^{-1}$
• D. $16N{C}^{-1}$

Answer 1

The correct option is B $32N{C}^{-1}$

Using formula $E=\frac{1}{4\pi {\epsilon }_0}\frac{Q}{r^2}$

So, substituting $r=3m$

$Q=32\times {10}^{-9}C$

We get $E=9\times {10}^9\times \frac{32\times {10}^{-9}}{(3{)}^2}C$

$E=32N{C}^{-1}$