Electrostatics Unit 1

Study Notes

Properties of electric charges: Conservation of charge, Coulomb's law (force between charges), superposition principle (force from multiple charges).
Electric field: Definition, field due to a point charge, electric field lines, electric dipole and its field, torque on a dipole in a uniform field.
Gauss's law: Statement, application to an infinitely long straight wire, uniformly charged plane sheet, and thin spherical shell.
Electric potential: Definition, potential difference, potential due to a point charge, dipole, and system of charges. Equipotential surfaces. Potential energy of a system of two charges and a dipole in an electric field.
Conductors and insulators: Free and bound charges inside a conductor, dielectrics and electric polarization.
Capacitors: Capacitance, combination of capacitors in series and parallel, parallel plate capacitor with and without a dielectric, energy stored in a capacitor.
Van de Graaff Generator

Ohm's Law, electrical resistance, current-voltage characteristics (linear and non-linear).
Electrical energy and power, electrical resistivity and conductivity, carbon resistors and their colour codes.
Series and parallel combinations of resistors.
Temperature dependence of resistance.
Internal resistance of a cell, potential difference and EMF of a cell, combination of cells in series and parallel.
Kirchhoff's laws and simple applications (Wheatstone bridge, metre bridge).
Potentiometer: principle and applications (measure potential difference and EMF, measure internal resistance of a cell).

Magnetic field: Concept, Oersted's experiment.
Biot-Savart law: Application to a current carrying circular loop.
Ampere's Law: Application to an infinitely long straight wire.
Straight and toroidal solenoids.
Force on a moving charge in a uniform magnetic and electric field (Cyclotron).
Force on a current carrying conductor in a uniform magnetic field, force between two parallel current carrying conductors (definition of ampere).
Torque on a current loop in a uniform field; moving coil galvanometer. Its current sensitivity and conversion to ammeter and voltmeter.
Current loop as a magnetic dipole and its dipole moment. Magnetic dipole moment of a revolving electron.
Magnetic field intensity due to a magnetic dipole along its axis and perpendicular to its axis. Torque on a magnetic dipole in a uniform field. Bar magnet as an equivalent solenoid, magnetic field lines.
Earth's magnetic field and magnetic elements.
Para-, dia-, and ferromagnetic substances. Electromagnets and factors influencing their strengths. Permanent magnets.

Electromagnetic induction: Faraday's law, induced EMF and current, and Lenz's Law.
Eddy currents.
Self and mutual induction.
Alternating currents: Peak and RMS values of alternating current/voltage, reactance and impedance.
LC oscillations (qualitative treatment), LCR series circuit, resonance, power in AC circuits (wattless current).
AC generator and transformer.

Electromagnetic waves: Characteristics.
Electromagnetic spectrum: Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays (uses).

Reflection of light: Spherical mirrors (mirror formula).
Refraction of light: Total internal reflection, optical fibers, refraction at spherical surfaces, lenses (thin lens formula, lensmaker's formula, magnification, power of a lens), combinations of thin lenses.
Refraction through a prism: Dispersion of light, scattering of light (explanation of blue sky and reddish appearance of the sun).
Optical instruments: Human eye, image formation, accommodation, correction of eye defects (myopia, hypermetropia, astigmatism), microscopes and astronomical telescopes.
Wave optics: Wavefront, Huygens’ principle, reflection and refraction of plane waves, interference (Young’s double slit experiment), diffraction (single slit).
Resolving power of microscopes and telescopes. Polarization, plane polarized light, Brewster's Law, uses of plane polarized light and polaroids.

Alpha-particle scattering experiment, Rutherford's model of atom, Bohr model, energy levels of hydrogen.
Composition and size of the nucleus, atomic masses, isotopes, isobars, isotones.
Radioactivity: Alpha, beta, and gamma particles/rays, their properties, radioactive decay law, mass-energy relation, mass defect, binding energy per nucleon (nuclear fission, fusion).

Semiconductor diode - I-V characteristics (in forward and reverse bias), diode as a rectifier.
I-V characteristics of transistor, transistor as an amplifier (common emitter configuration), basic idea of analog and digital signals. Logic gates (OR, AND, NOT, NAND, NOR). Transistor as a switch.

Communication system (block diagram only). Bandwidth of signals (speech, TV, digital data). Bandwidth of transmission medium.
Propagation of electromagnetic waves in the atmosphere, sky wave propagation, satellite communication.
Need for modulation, amplitude modulation. Production and detection of an amplitude modulated wave.