10th Class Physics Chapter 7 Notes Urdu Medium

Complete Notes on Chapter No.16: 10th Class Physics Chapter 7 Notes Urdu Medium written by Professor Sir Fahad Abbas Suib. These computerized notes are very helpful in the preparation of Basic Electronics Class 10 for students of Physics and these are according to the paper patterns of all Punjab boards.

• Our comprehensive 10th Class Physics Chapter 7 Notes Urdu Medium will ensure you're fully prepared for your exams.
• Explain the process of thermionic emission emitted from a filament.
• Describe the simple construction and use of an electron gun as a source of electron beam.
• Describe the effect of electric field on an electron beam.
• Describe the effect of magnetic field on an electron beam.
• Describe the basic principle of CRO and make a list of its uses.
• Differentiate between analogue and digital electronics.
• State the basic operations of digital electronics.
• Identify and draw the symbols for the logic gates (NOT, OR, AND, NOR and NAND).
• State the action of the logic gates in truth table form.
• Describe the simple uses of logic gates.
• What is Basic Electronics?  Basic electronics comprises the minimal "electronics components" that make up a part of everyday electronics equipment. These electronic components include resistors, capacitors, diodes, inductors, etc. Powered by a battery, they are designed to work under certain physics laws and principles. Basic electronics also concerns the measurement of voltage, current (electron flow), and resistance in the assembled working "circuit."
• Field, and thus, carriers in the partially filled bands can contribute to the electrical conductivity of the material. In the case of metals, the electronic band structure results in incomplete filling of the highest occupied energy band. If an electron acquires enough additional energy from an external source, it leaves the valence shell becomes a free electron, and exists in what is known as the conduction band.
• The difference in the energy between the valence band and the conduction band is called the energy gap. This is the amount of energy that an electron must have in order to jump from the valence band to the conduction band. Once in the conduction band the election is free to move throughout the material and is not tied to any given atom.
• Electronics is that branch of applied physics which deals with the control of motion of electrons using different devices. Electronic devices being more effective and reliable have revolutionized the fields of telecommunication and information technology. This chapter aims at providing basic concepts of electronics.
• THERMIONIC EMISSION: In the 1850's, physicists started to examine the passage of electricity through a vacuum by putting two electrodes in a sealed vacuum tube. Some kind of rays were emitted from the cathode or the negative electrode. These rays were called cathode rays. J.J. Thomson in 1897 observed the deflection of cathode rays by both electric and magnetic fields. From these deflection experiments, he concluded that cathode rays must carry a negative charge. These negatively charged particles were given the name electrons.
• The process of emission of electrons from the hot metal surfaces is called thermionic emission. Metals contain a large number of free electrons. At room temperature electrons cannot escape the metal surface due to attractive forces of the atomic nucleus. If the metal is heated to a high temperature, some of the free electrons may gain sufficient energy to escape the metal surface.
• Thermionic emission can also be produced by electrically heating a fine tungsten filament. Typical values of the voltage and current used are 6 V and 0.3 A respectively. Now we examine some important experiments performed for discovering the properties of the electrons.
• INVESTIGATING THE PROPERTIES OF ELECTRONS:
• An electron gun is used to investigate the properties of electron beam. The electrons are produced by thermionic emission from a tungsten filament heated by 6V supply. A high positive potential (several thousands) is applied to a cylindrical anode (+). The electrons are accelerated to a high speed and pass through the hole of the anode in the form of a fine beam of electrons. The whole set up is fitted in an evacuated glass bulb.
• High Voltage supply, Emitting electrons, Filament supply, Heated filament