Q. A copper sphere of diameter $1,m$ carries a charge of $200 mu C$. A test charge of $2mu C$ is taken from a point $P$ to a point $Q$ on the opposite sides of the sphere. Both points are at a distance of $1,m$ from the centre of the sphere. What is the work done ?

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A copper sphere of diameter $1,m$ carries a charge of $200 mu C$. A test charge of $2mu C$ is taken from a point $P$ to a point $Q$ on the opposite sides of the sphere. Both points are at a distance of $1,m$ from the centre of the sphere. What is the work done ?

Solution:

Both points are on equipotential surface.