Important Derivations of class 12 Physics (Unit wise)
UNIT – 1 ELECTROSTATICS
- Electric field intensity due to a dipole
- Behavior of dipole in a uniform electric field.
- Gauss’s theorem and its applications to find field due to
- infinitely long straight wire
- uniformly charged infinite plane sheet
- two parallel sheets and
- uniformly charged thin spherical shell (inside and outside).
- Parallel plate capacitor with and without dielectric medium.
- Energy stored in a capacitor.
UNIT – 2 CURRENT ELECTRICITY
Drift velocity and mobility and their relation with electric current. Kirchoff’s law – illustration by simple circuits – Wheatstone’s Bridge Metrebridge – Special case of Wheatstone bridge – Potentiometer – principle & comparing the emf of two cells.
UNIT – 3 EFFECTS OF ELECTRIC CURRENT
Biot-Savart law – Magnetic field due to an infinitely long current carrying straight wire and circular coil – Construction and working – Bar magnet as an equivalent solenoid – magnetic field lines. Ampere’s circuital law. Force on a moving charge in uniform magnetic field and electric field, forces between two parallel current carrying conductors . Torque experienced by a current loop in a uniform magnetic field-moving coil galvanometer – Conversion to ammeter and voltmeter
UNIT – 4 ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT
Self-inductance of a long solenoid – mutual inductance of two long solenoids. AC generator – (Single phase, three phase). Transformer – Alternating current – measurement of AC – AC circuit with resistance – AC circuit with inductor – AC circuit with capacitor – LCR series circuit – Resonance and Q – factor: power in AC circuits.
UNIT–5 ELECTROMAGNETIC WAVES AND WAVE OPTICS
Wavefront and Huygen’s principle – Proving laws of Reflection, Refraction. Interference – Young’s double slit experiment and expression for fringe width – coherent source – interference of light. Formation of colours in thin films – Diffraction – differences between interference and diffraction of light. Uses of plane polarised light and Polaroids – rotatory polarisation.
UNIT – 6 ATOMIC PHYSICS
Hydrogen spectrum – energy level diagrams – sodium and mercury spectra – excitation and ionization potentials.
UNIT – 7 DUAL NATURE OF RADIATION AND MATTER – RELATIVITY
Einstein’s photo – electric equation – laws of photo – electric emission – work function. De–Broglie relation – De–Broglie wave length of an electron – electron microscope.
UNIT – 8 NUCLEAR PHYSICS
Nuclear Radii, masses, binding energy – Nuclear mass defect – binding energy. Radioactivity – alpha, beta and gamma radiations, Radioactive decay law – half life – mean life.
UNIT – 9 SEMICONDUCTOR DEVICES AND THEIR APPLICATIONS
Formation of P-N Junction – Barrier potential and depletion layer. – P-N Junction diode – Forward and reverse bias characteristics – diode as a rectifier – zener diode. Zener diode as a voltage regulator – LED. Transistor as an amplifier – Logic gates – NOT, OR, AND, EXOR using discret components – NAND and NOR gates as universal gates.
UNIT – 10 COMMUNICATION SYSTEMS
Receiver & transmission antenna relationship.
