Satya Prakash Electricity And Magnetism Pdf May 2026

鈥淎 point charge q is placed at a distance d from the center of an uncharged conducting sphere of radius R (R < d). Find the force on the charge. Verify that the force is always attractive, no matter the sign of q.鈥�

What if it wasn鈥檛?

Professor Ananya Rao had taught electricity and magnetism for thirty-one years. She could derive Maxwell鈥檚 equations in her sleep, calculate the magnetic field of a toroid while chopping onions, and explain Lenz鈥檚 law to a room of hungover sophomores without once checking her notes.

She鈥檇 skipped a term. A term involving the second derivative of the potential鈥攁 term that, for a perfect conductor, should cancel exactly. But her cancellation required the sphere to be infinitely conducting. Perfectly rigid in its response.