What is Secondary Emission? When a beam of high velocity electrons suddenly strikes a metallic surface, they give up their kinetic energy to electrons and atoms which they strike. Some of the bombarding electrons, called…
What is Thermionic Emission? A very common method used for electron emission is by heating the metal piece to a high temperature. The process of electron emission from the surface of metal into the surrounding…
What is Electron Emission? The liberation of electrons from the surface of a substance is known as electron emission. For electron emission, metals are employed because they have many free electrons. In a metal like…
Electron Orbits and Energy Levels: As already discussed above electron orbits can occupy only certain rings or shells at fixed distances from the nucleus. These shells may be circular or elliptical and are numbered as…
Explain Bohr's Atomic Model: Bohr's Atomic Model - Neils Bohr, a Danish physicist, put forward his model of atom in 1913. He retained Rutherford's model of a very small positively charged nucleus at the centre.…
Motion in Combined Electric and Magnetic Fields: The Motion in Combined Electric and Magnetic Fields is given by the below two names, namely Parallel Electric and Magnetic Fields Perpendicular Electric and Magnetic Fields Parallel Electric…
Motion of an Electron in a Magnetic Field: Motion of an Electron in a Magnetic Field - Consider an electron to be placed in the region of magnetic field. If an electron is at rest,…
Force in a Magnetic Field: Force in a Magnetic Field - If a conductor of length l metres carrying current I amperes is placed in a magnetic field of intensity B (tesla), and if B…
Two Dimensional Motion in a Uniform Electric Field: Two Dimensional Motion in a Uniform Electric Field - Let us consider that an electron enters the region between two parallel plates of a parallel plate capacitor…
What is Current Density? By definition, the current density, denoted by the symbol J, is the current per unit area of the conducting medium i.e., where current I is the rate of flow of charge.…