The minimum work needed to be done to bring a charge $q=6 \mu \mathrm{C}$ from $\infty$ to a point $0.75 \mathrm{~m}$ from a charge $Q=30 \mu \mathrm{C}$ is

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Aicharya · Accepted Answer

Given, first charge, $q=6 \mu \mathrm{C}$ $ =6 	imes 10^{-6} \mathrm{C} $ Charge, $Q=30 \mu \mathrm{C}$ $ =30 	imes 10^{-6} \mathrm{C} $ Final distance, $r_f=0.75 \mathrm{~m}$ Initial distance, $r_i=\infty$ Since, work $(W)=k Q q\left[\frac{1}{r_f}-\frac{1}{r_i}ight]$ where, $k$ is Coulomb's constant $=9 	imes 10^9 \mathrm{C}^2 \mathrm{~kg}^{-2} \mathrm{~N}^{-1}$ $ \begin{aligned} 	herefore \quad W & =9 	imes 10^9 	imes 6 	imes 10^{-6} 	imes 30 	imes 10^{-6}\left(\frac{100}{75}-0ight) \ & =2.16 \mathrm{~J} \end{aligned} $

The minimum work needed to be done to bring a charge $q=6 \mu \mathrm{C}$ from $\infty$ to a point $0.75…

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