It is the emission of electrons from the surface of certain substances, mainly metals, when they are illuminated by electromagnetic radiations like X-rays, ultraviolet and even visible light. The electrons emitted are called photo electrons. Experiment to Demonstrate Photoelectric Effect: In figure (a) A and C are two zinc plates, connected to positive and negative Read more about Photo Electric Effect[…]
General form of Ohm’s law: At a constant temperature potential difference across a conductor is directly proportional to the current passing through it V α I V = RI Ohm’s law is material dependent because it is defining resistance of the material. Those which obeys ohm’s law and are known as ohmic or linear conductor, Read more about Ohm’s law[…]
Consider a closed conducting loop ABCD, with the arm CD sliding, placed in a horizontal plane. Let B be a uniform magnetic field perpendicular to the plane of the loop and directed into it. Let the conductor CD be moved towards right with a velocity v as shown in Fig. As the conductor CD slides, Read more about Motional E.M.F[…]
The ability of a magnetic field to magnetize a material medium is called its magnetic intensity H. Its magnitude is measured by the number of ampere-turns flowing round unit length of a solenoid, required to produce that magnetic field. Let the field due to a solenoid of n turns per meter length be H = Read more about Magnetic Intensity (H):[…]
LENZ’S Law – The Direction of Induced E.M.F: The direction of the induced e.m.f. is given by the Russian Scientist Lenz. The direction of the induced e.m.f. is such that it opposes the cause producing the change of flux. Induced e.m.f.. This equation is called Faraday’s law of induction or Neumann’s law. The negative sign Read more about LENZ’S Law[…]
Faraday’s laws of electromagnetic induction-Magnitude of induced e.m.f. Whenever the magnetic flux linked with a closed circuit changes, an e.m.f. is induced in the circuit. The induced e.m.f. lasts so long as the change in flux lasts. The magnitude of the induced e.m.f. is directly proportional to rate of change of flux linkage or rate Read more about Laws of Electromagnetic Induction[…]
Kirchhoff’s Voltage Law: Kirchhoff’s voltage law states that the algebraic sum of all branch voltages around any closed loop of a network is zero at all instants of time. It is a consequence of the law of conservation of energy. Voltage being the energy (or work) per unit charge. A simple resistive network with voltage Read more about Kirchhoff’s Laws[…]
Inductor in series and parallel: We shall first consider an ideal voltage source applied to the series combination of N inductors. Applying KVL to the original circuit, Vs = V₁ + V₂ + … + Vn But for the equivalent circuit we have, And thus the equivalent inductance is Leq = (L₁ + L₂ + Read more about Inductor in Series and Parallel[…]
Consider a circuit containing an inductance L and a resistance R connected in series with a d.c. source of steady e.nif E volt and a tap key K (Morse key). When the key is pressed K is in contact with the point A, the current grows from zero to a maximum value of I₀. Let Read more about Growth of Current in an L – R Circuit[…]
Statement: The gauss’s theorem states that the total electric flux through any closed surface is equal to times the net charge enclosed by the surface. Total electric flux = x Net charge . . The circle on the integral means that the surface S is closed. The net charge means the algebraic sum of the Read more about Gauss Law[…]