Unit - I Electricity and Capacitance 1.1 Capacitors and capacitance. 1.2 Parallel plate capacitor, effect of dielelctric on capacitance 1.3 Combination of capacitors, energy stored in a capacitor 1.4 Cells, emf of cell, internal resistance of cell, kirchoff's laws, Wheatstone's bridge. 1.5 Potential gradient, potentiometer. Unit - II Radioactivity and Ultrasonic Waves 2.1 Radioactivity, particles / rays and their properties. 2.2 Radioactive decay law, half-life period. 2.3 Sound waves, amplitude, frequency, time-period wavelength and velocity of wave, relation between velocity, frequency and time period of wave. 2.4 Ultrasonic waves, properties of ultrasonic waves, 2.5 Piezo-electric effect, Piezo materials; Natural; Quartz, synthetic : Gallium orthophosphate. 2.6 Generation of ultrasonic waves using Piezo electric effect. 2.7 Applications of ultrasonic waves, 2.8 Doppler effect and its applications. Unit - III Photoelectricity, X-Rays and LASERs 3.1 Planck's hypothesis, properties of photons, photoelectric effect : threshold frequency, threshold wavelength, stopping potential, work function, characteristics of photoelectric effect. Einstein's photoelectric equation 3.2 Photoelectric cell and LDR principle, working and applications. 3.3 Production of X-ray by Modern Coolidge tube, Properties and applications of X-rays. 3.4 Laser, properties of laser, absorption, spontaneous and stimulated emission.3.5 Population inversion, active medium, optical pumping, three energy level system, He-Ne laser applications of laser.