Gyaan Series

TRANSISTORS   A transistor is a solid-state device made by joining three positive-type and negative-type semiconductors together. In general, all transistors have three pins: base , collector , and emitter . Transistor is a bi-polar device that is a transistor with two junctions namely BE and CE DE EE FE. In theory we take a specified formulae incorporate this with using any type of meter in figuring the mathematical solution.  A Transistor is a three terminal semiconductor device that regulates current or voltage flow and acts as a switch or gate for signals. Why Do We Need Transistors? Suppose that you have a FM receiver which grabs the signal you want. The received signal will obviously be weak due to the disturbances it would face during its journey. Now if this signal is read as it is, you cannot get a fair output. Hence we need to amplify the signal. Amplification means increasing the signal strength. This is just an instance. Amplification is needed wherever the si

INDUCTORS Let me introduce you to another important component in the field of Electronics and Electricals, the Inductor. Inductor is a passive two-terminal component that temporarily stores energy in the form of a magnetic field. It is usually called as a coil. The main property of an inductor is that it opposes any change in current. According to the Faraday’s law of Electromagnet ic induction, When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor. According to lens law, the direction of induced EMF opposes the change in current that created it. Hence, induced EMF is opposite to the voltage applied across the coil. This is the property of an inductor.  An inductor blocks any AC component present in a DC signal. The inductor is sometimes wrapped upon a core, for example a ferrite core. It then looks as in the figure below. Symbols: The symbols of various types of inductors are as given below

TYPES OF CAPACITORS There are many types of capacitors depending upon their function, the dielectric material used, their shape etc. The main classification is done according to fixed and variable capacitors.  The main classification is just like the above one. The fixed capacitors are the ones whose value is fixed at the time of manufacturing itself and the variable ones provide us with an option to vary the value of capacitance.   Types: There are different types of capacitors available in the market. The key factor in distinguishing different types of capacitors is the Dielectric used in its construction. Some of the common capacitor types are ceramic, electrolytic (which include Aluminium capacitors, Tantalum capacitors and Niobium capacitors), plastic film, paper and mica. Each capacitor type has its own advantages and disadvantages. The characteristics and areas of applications may vary from one capacitor to other. Hence, when choosing a capacitor, following few o

CAPACITOR COLOR CODING To know the value of a capacitor , it is usually labelled as below − n35 = 0.35nF or 3n5 = 3.5nF or 35n = 35nF and so on . Sometimes the markings will be like 100K which means, k = 1000pF . Then the value will be 100 × 1000pF = 100nF . Though these number markings are being used now-a-days, an International colour coding scheme was developed long ago, to understand the values of capacitors. In these five band capacitors, the first two bands represent digits, third one indicates multiplier, fourth for tolerance and the fifth represents voltage.

CAPACITORS A Capacitor is a passive component that has the ability to store the energy in the form of potential difference between its plates. It resists a sudden change in voltage. The charge is stored in the form of potential difference between two plates, which form to be positive and negative depending upon the direction of charge storage. A non-conducting region is present between these two plates which is called as dielectric. This dielectric can be vacuum, air, mica, paper, ceramic, aluminum etc. The name of the capacitor is given by the dielectric used. Symbol and Units: The standard units for capacitance is Farads. Generally, the values of capacitors available will be in the order of micro-farads, pico-farads and nano-farads.  The Capacitance of a capacitor is proportional to the distance between the plates and is inversely proportional to the area of the plates. Also, the higher the permittivity of a material, the higher will be the capacitance. The permitt

RESISTORS COLOR CODE A process called colour coding  is used to determine the value of resistance for a resistor, just as shown in the above figure. A resistor is coated with four color bands where each colour determines a particular value. The below table shows a list of values which each colour indicates.  The first two coloured bands indicate the first and second digit of the value and the third colour band represents the multiplier (number of zeroes added). The fourth colour band indicates the tolerance value. Tolerance: Tolerance is the range of value up to which a resistor can withstand without getting destroyed. This is an important factor. The following figure shows how the value of a resistor is determined by colour code.  The five colour band resistors are manufactured with tolerance of 2% and 1% and also for other high accuracy resistors. In these five band resistors, the first three bands represent digits, fourth one indicates multiplier and the f

RESISTORS Resist is the word which means “ to oppose ”. Resistance is the property of opposing the flow of electrons, in a conductor or a semiconductor. A Resistor is an electronic component which has the property of resistance. Symbol and Units: The symbol for a Resistor is as shown below  The units of resistance is  Ohms , which is indicated by Ω (omega) . The formula for resistance is R = V/I Where  V  is Voltage and  I  is Current . It would really be difficult to manufacture the resistors with each and every value. Hence, few values are chosen and the resistors of such values are only manufactured. These are called as “ Preferred Values ”. In practice, the resistors with near values are chosen to match the required applications.