Why they did Eout - Ein Please explain this This is the Potential due to a Uniform Solid - Physics - Electrostatic Potential And Capacitance

Question

Why they did Eout - Ein? Please explain this This is the Potential
due to a Uniform Solid Sphere of Charge

Akhilesh Kumar Chauhan · Accepted Answer

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Rest part is already solved in question posted by you

Why they did Eout - Ein? Please explain this. This is the Potential due to a Uniform Solid Sphere of Charge.