A particle of mass $2\times {10}^{-3}$ kg, charge $4\times {10}^{-3}$ C enters in an electric field of 5 V/m, then its kinetic energy after 10 s is

Here, $\mathrm{q}=4\times {10}^{-3} \mathrm{C}, \mathrm{E} = 5 \mathrm{V}/\mathrm{m},$

          t = 10 s, $\mathrm{m}=2\times {10}^{-3} \mathrm{kg}$

The KE of charged particle $=\frac{{\mathrm{q}}^2{\mathrm{E}}^2{\mathrm{t}}^2}{2\mathrm{m}}$

                                            $=\frac{{\left(4\times {10}^{-3}\right)}^2\times (5{)}^2\times (10{)}^2}{2\times 2\times {10}^{-3}}$

$\therefore$                                   KE = 10 J