Physics · Class 12 · Chapter 1
Electric Charges and Fields
13 lessons 108 min 2 simulations
This chapter is electrostatics: charges at rest and the forces and fields they produce. It starts with what charge is and how bodies get it, sets out its three properties (additivity, conservation, quantisation), states Coulomb's law and the superposition principle, and then builds the electric field, field lines, electric flux, the electric dipole and Gauss's law, which it uses to find the field of a long wire, a flat sheet and a spherical shell.
What the exam asks
NEET asks for Coulomb-force ratios when charge or distance changes, the net force or field from several charges by vector addition, the dipole field on the axis and the equator, torque on a dipole, flux through a closed surface from Gauss's law, and the fields of a line, sheet and shell. Marks are lost by forgetting that force and field are vectors, by using 1/r² for a dipole, and by counting charges outside a Gaussian surface in q_enclosed.
Lessons
13 lessons · 108 min
1Electric charge, conductors and insulatorsNCERT §1.2 and §1.37 min2Basic properties of electric chargeNCERT §1.47 min3Coulomb's lawNCERT §1.510 min 1 sim4Forces between multiple chargesNCERT §1.66 min5Electric fieldNCERT §1.77 min6Electric field linesNCERT §1.87 min7Electric fluxNCERT §1.97 min8Electric dipoleNCERT §1.107 min9Dipole in a uniform external fieldNCERT §1.1111 min 1 sim10Continuous charge distributionNCERT §1.127 min11Gauss's lawNCERT §1.137 min12Applications of Gauss's lawNCERT §1.148 min13Chapter reviewMust-know facts, traps and formulas17 min