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WELCOME. Resistor, Inductor & Capacitor. Prepared By :. Guided By : Prof. Krishna B. Chauhan. Devpura Lavika U. (130410109021) Mehta Yashvi M. (130410109048) Prajapati Yogeshwari M. (130410109086) Shah Dhruti M. (130410109097). Elements of Electrical Engineering (2110005).
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Resistor, Inductor & Capacitor Prepared By : Guided By : Prof. Krishna B. Chauhan Devpura Lavika U. (130410109021) Mehta Yashvi M. (130410109048) Prajapati Yogeshwari M. (130410109086) Shah Dhruti M. (130410109097) Elements of Electrical Engineering (2110005)
Certificate This is to certify that Devpura Lavika U. (130410109021) Mehta Yashvi M. (130410109048) Prajapati Yogeshwari M. (130410109086) Shah Dhruti M. (130410109097) of Electrical Engineering Department has completed their Active Learning Assignment for the subject Elements of Electrical Engineering (2110005) for the term ending in December, 2013. DATE: 28/11/2013 3
Contents:: • Introduction • Resistor • Types of resistor • Inductor • Types of inductor • Flux in inductor • I - V relation of inductors • Capacitor • Types of capacitor • Charge in capacitors • I -V relation of capacitors • Comparisons between three quantities
Basic Circuit Elements There are 5 basic circuit elements: Voltage sources Current sources Resistors Inductors Capacitors We will introduce resistors, inductors & capacitors.
Introduction Resistor : A passive element which dissipates energy only. Two important passive linear circuit elements: Capacitor Inductor Capacitor and inductor can store energy only and they can neither generate nor dissipate energy. 6
Resistor • Resistance is a property of material due to which it opposes the flow of current through it. • When electrons flow through any material, they collide with each other which gives rise to opposition to the flow of current. • The unit of resistor is ohm(Ω).
Resistor … • The resistance of a conductor will be 1Ω when it allows 1 A current to flow through it on application of 1 V across its material. • The resistance of conducting material is found to … • be directly proportional to the length l of the material, • be inversely proportional to the cross-sectional area of the material. • depend on the nature of material. • depend upon the temperature.
Resistor… • Therefore, R ∞ l/a or R = ρl/a • Where, R=resistance in Ω l=length in m a =cross section area in m² ρ= resistivity in Ω-m
Types of resistor • There are many different Types of Resistors available to the electronics constructor, from very small surface mount chip resistors up to large wirewound power resistors. • They are described as below : • Carbon Composition Resistors • Carbon Film Resistors • Metal Film Resistors • Thick Film Resistors • Thin Film Resistors • Wirewound Resistors • Surface Mount Resistors
Types of resistor… • Carbon Composition Resistors : • Carbon composition resistors used to be the most common type of resistors used in electronics due to their relative low cost and their great reliability. • Carbon composition resistors use a solid block of material made from carbon powder, an insulating ceramic, and a binder material. 2. Carbon Film Resistors : • Carbon film resistors use a thin layer of carbon on top of an insulating rod which is cut to form a narrow, long resistive path. • By controlling the length of the path and its width, the resistance can be precisely controlled with tolerances as tight as 1%.
Types of resistor… • Metal Film Resistors : • One of the more common axial resistor types used today are metal film resistors. • They are very similar in construction to carbon film resistors, with the main difference being the use of a metal alloy as the resistive material rather than carbon. • Thick Film Resistors : • They are made in a screen printing process using a conductive ceramic and glass mixture composite suspended in a liquid. • Once the resistor has been screen printed, it is baked at high temperatures to remove the liquid and fuse the ceramic and glass composite.
Types of resistor… • Thin Film Resistors : • Borrowing from semiconductor processes, thin film resistors are made by through a vacuum deposition process called sputtering where a thin layer of conductive material is deposited on an insulating substrate. • This thin layer is then photo etched to create a resistive pattern. • By precisely controlling the amount of material deposited and the resistive pattern, tolerances as tight as 0.01% can be achieved with thin film resistors. 6. Wirewound Resistors : • They are made in a screen printing process using a conductive ceramic and glass mixture composite suspended in a liquid. • Once the resistor has been screen printed, it is baked at high temperatures to remove the liquid and fuse the ceramic and glass composite.
Types of resistor… • Surface Mount Resistors : • Surface Mount Resistors or SMD Resistors, are very small rectangular shaped metal oxide film resistor. • The resistive value of the resistor is controlled by increasing the desired thickness, length or type of deposited film being used and highly accurate low tolerance resistors, down to 0.1% can be produced.
Inductor An inductor is made of a coil of conducting wire. An inductor is a passive element designed to store energyin the magnetic field while a capacitor stores energy in the electric field. 17
The unit ([Henry] or [H]) is named for Joseph Henry, and is equal to a [Volt-second/Ampere]. Joseph Henry (1979-1878) 18
Types of Inductor • air-core • (b) iron-core • (c) variable iron-core 19
Flux in Inductors The relation between the flux in inductor and the current through the inductor is given below. Linear ψ Nonlinear i 20
I-V Relation of Inductors Aninductor consists of a coil of conducting wire. i v L + - 21
Capacitors A capacitor consists of two conducting plates separated by an insulator (or dielectric). The symbol use for capacitor in the circuit diagram is :: 23
Capacitors… A capacitor is a two terminal circuit element that has a current through its terminals which is proportional to the derivative of the voltage across its terminals. The coefficient of this proportionality is the defining characteristic of a capacitor. A capacitor is the device that we use to model the effect of electric fields on circuit variables. The energy stored in electric fields has effects on voltage and current.
Michael Faraday (1971-1867) • The unit of capacitor is Faraday. 25
Capacitors Three factors affecting the value of capacitance: Area: the larger the area, the greater the capacitance. Spacing between the plates: the smaller the spacing, the greater the capacitance. Material permittivity: the higher the permittivity, the greater the capacitance. Where, 26
Types of Capacitors (a) Polyester capacitor, (b) Ceramic capacitor, (c) Electrolytic capacitor 27
Types of Capacitors… Variable capacitors 28
Charge in Capacitors The relation between the charge in plates and the voltage across a capacitor is given below. Linear Nonlinear q v 29
I-V Relation of Capacitor + i C v - 30