Physics · Class 12 · Chapter 3
Current Electricity
12 lessons 111 min 5 simulations 9 practice questions
This chapter deals with charges in steady motion through conductors. It defines current and current density, states Ohm's law, explains resistance at the microscopic level through the drift of free electrons, looks at how resistivity changes with material and temperature, and then treats electrical power, cells with internal resistance, combinations of cells, Kirchhoff's rules and the Wheatstone bridge.
What the exam asks
NEET tests drift speed, how resistance changes when a wire is stretched or heated, terminal voltage of a cell with internal resistance, cells in series and parallel, Kirchhoff's-rule networks, the balanced Wheatstone bridge, and power shared between bulbs. Marks are usually lost on unit conversion (mm² to m²), on sign errors in loop equations, and on assuming a bridge is balanced without checking the ratios.
Lessons
12 lessons · 111 min
1Electric currentNCERT § "Electric Current"7 min2Electric currents in conductors and Ohm's lawNCERT § "Ohm's Law"11 min 1 sim3Electron drift and where resistivity comes fromNCERT § "Drift of Electrons and the Origin of Resistivity"11 min 1 sim4MobilityNCERT § "Mobility"6 min5Limitations of Ohm's lawNCERT § "Limitations of Ohm's Law"7 min6Resistivity of materials and its temperature dependenceNCERT § "Resistivity of Various Materials" and § "Temperature Dependence of Resistivity"6 min7Electrical energy and powerNCERT § "Electrical Energy, Power"7 min8Cells, emf and internal resistanceNCERT § "Cells, emf, Internal Resistance"10 min 1 sim9Cells in series and in parallelNCERT § "Cells in Series and in Parallel"10 min 1 sim10Kirchhoff's rulesNCERT § "Kirchhoff's Rules"8 min11Wheatstone bridgeNCERT § "Wheatstone Bridge"10 min 1 sim12Chapter reviewMust-know facts, traps and formulas18 min