The work done in moving an electric charge $q$ in an electric field does not depend upon

The electric potential of the Earth is taken to be zero because the Earth is a good:

When a charge of $20 C$ is taken from one point to another separated by a distance of $0.2 m$,work of $2 J$ is required to be done. What is the potential difference between the two points?

$A$ hollow charged metal sphere has radius $R$. If the potential difference between its surface and a point at a distance $5R$ from the centre is $V$,then the magnitude of the electric field intensity at a distance $5R$ from the centre of the sphere is:

The work done in moving a charge of $20 \ C$ from point $A$ to point $B$ is $2 \ J$. What is the potential difference between the two points (in $V$)?

$A$ hollow metal sphere of radius $5\, cm$ is charged such that the potential on its surface is $10\, V$. The potential at the centre of the sphere is