What is resistor :

A resistance may be a passive two-terminal electrical part that implements resistivity as a circuit part. In electronic circuits, resistors are accustomed to cut back current flow, change signal levels, to divide voltages, bias active components, and terminate transmission lines, among different uses. Resistors limit or limit the flow of current during a circuit. the flexibility of a fabric or part to resist current flow is measured in ohms. This potential drop balances out the energy lost. once employed in DC circuits the potential drop, additionally referred to as a resistors fall, is measured across the terminals because the circuit current flows through the resistance.



                        Fig: Resistor 

Types of Resistor :

Fixed Resistor: fastened resistors square measure out and away the foremost wide used style of a resistor. they’re employed in natural philosophy circuits to line the proper conditions during a circuit. Their values square measure determined throughout the planning part of the circuit, and that they ought to ne’er have to be compelled to be modified to “adjust” the circuit.


Variable Resistor: These electrical devices include a set resistor part and a slider that faucets onto the most resistor part. this provides 3 connections to the component: 2 connected to the fastener part, and also the third is that the slider. during this means, the element acts as a variable resistance if all 3 connections square measure used.

Standard Resistor Symbol :

It avoids employing a decimal centrifuge and replaces the decimal centrifuge as shortly as a letter loosely associated behind SI prefixes corresponding considering the share’s resistance. as an example, 8K2 as half marking code, in a very circuit diagram or in a very credit of materials (BOM) indicates a resistance worth of eight.2 k. further zeros imply a tighter tolerance, as an example, 15M0 for 3 vital digits. The terminals of the resistance square measure every one of the lines extending from the squiggle (or rectangle). Those square measure what be neighboring to the burning of the circuit.


                 Fig: Resistor Symbol

Resistor Unit :

The tale for an ohm is the greek capital-omega. The (somewhat roundabout) definition of 1 is the resistance in the midst of two points where 1 volt (1V) of the applied potential cartoon will shove 1 ampere (1A) of current. larger or smaller values of ohms can be matched behind a prefix at the forefront kilo-, mega-, or giga-, to make large values easier to gate. It is totally common to see resistors in the kilohm (k) and megaohm (M) range.

Resistor in Series :

Resistors are asynchronous whenever the flow of charge, referred to as the present, should flow through devices consecutive. It looks affordable that the whole resistance is that the addition of the individual resistances, considering that the present needs to labor under every resistance in sequence. the whole resistance of the circuit is found by merely adding up the resistance values of the individual resistors.


          Fig: Series Circuit Diagram

Resistor in Parallel :

The current during a loop breaks up, with some flowing on every parallel branch and re-combining once the branches meet once more. during this case the present provided by the battery splits up, and also the quantity probing every resistance depends on the resistance. several circuits have a mix of series and parallel resistors. Generally, the overall resistance during a circuit like this is often found by reducing the various series and parallel combos stepwise to finish up with one equivalent resistance for the circuit. this permits the present to be determined simply. the present flowing through every resistance will then be found by undoing the reduction method.


           Fig: Parallel Circuit Diagram

resistor in Series and Parallel :

Resistors are connected along in an infinite range of series and parallel mixtures to create complicated resistive circuits. the tactic of shrewd the circuits equivalent resistance is that the same as that for somebody series or loop and hopefully, we tend to currently grasp that resistors asynchronous carry precisely the same current which resistors in parallel have precisely the same voltage across them.


            Fig: Mix Circuit Diagram

1st look this could appear a troublesome task, however if we glance a touch nearer we will see that the 2 resistors, R2 and R3 are literally each connected along in an exceedingly “SERIES” combination thus we will add them along to supply the same resistance an equivalent as we tend to do within the series resistance tutorial. thus our circuit currently features a single resistance RA in “PARALLEL” with the resistance R4. exploitation our resistors in an exceedingly parallel equation.