Current Electricity

This chapter extends electrostatics to charges in motion. You'll learn how electric current arises in conductors, derive Ohm's law from the microscopic picture of drifting electrons, understand resistivity and its temperature dependence, analyse energy and power in circuits, study cells along with their series/parallel combinations, and master the two big circuit-analysis tools used in Boards, JEE, and NEET: Kirchhoff's rules and the Wheatstone bridge. The potentiometer rounds off the chapter as a precision measurement device.