1.
An absolute guide from ABC to XYZ.
Resistor

2.
a) An electrical component which provides
resistance to current flow
b) Most commonly used electrical
component
What is Resistor

3.
Resistance
• It is the ability of resistor to oppose flow of current
• It is Measured in unit ‘Ohms’ and denoted by unit Ω
• Different prefixes are used to represent Resistance
• Three most commonly used prefixes are:
Resistance Prefix
1000 1k
1,000,000 1M
1,000,000,000 1G

4.
Symbols
1. Internationally a zig-zag model is used to represent the resistors.
2. Whereas in UK most people use the symbol on left.

5.
Types of Fixed Resistors ( Design Models)
Carbon film Metal film Metal Oxide
Wire wound resistors

6.
Types of Resistors
Potentiometer
It provides variable resistance.
Phototransistor Tapped Resistor

7.
• These are inexpensive and are very easily available resistors.
• These resistors are available in Ranges 1Ω to 100 MΩ
• The power ratings are in between 0.125-2W.
Cons
• There is a large tolerance in rating and mostly 5-10% difference is
expected.
• Such resistors are recommended for small applications like experiments
in labs. But are not recommended for large applications.
Carbon Film Resistors

8.
• They re expensive compared to Carbon
Film resistors
• Are highly recommended for projects
Metal Film Resistors

9.
• They have special ability to dissipate large quantities of heat.
• These are recommended when there is large variation in temperatures.
• Such resistors contain porcelain which is covered by metal (usually steel
or some kind of mixed steel alloy).
• This steel alloy is then again coated with porcelain
• Remember that porcelain has property to absorb heat through
conductors.
Wire wound resistors

10.
• Such resistors are enclosed in IC’s
• They are expensive as compared to single resistor but are quite easy to
manage.
• Can be used where you require 4 or more resistors and less space is
available
Integrated Resistors

11.
• They provide variable resistance.
• Are required when you need variable values, for example you may need 7k ohm.
• Have large values of applications in motor speed control, fan speed control, radio
frequecnies.
Variable Resistor (Potentiometer)
Symbol
Practical Look
Working

12.
• Its resistance depends on the temperature
• If temperature changes the value of resistance changes.
Thermistor
How it looks
Symbol

13.
• NTC stands for negative temperature coefficient.
• The resistance of such resistors decreases with increase in temperature.
• Such resistors are installed in parallel
NTC Thermistor (Continue)
Resistancealongy-axis
Temperature along x-axis

14.
• PTC stands for positive temperature coefficient
• The resistor of such components increases with temperature
• They are mostly loaded in parallel
PTC Thermistor Continue
Resistancealongy-axis
Temperature along x-axis

15.
• Used to identify the values of resistors.
• A color code chart is used for reference.
Resistor Color coding

16.
• Resistors in circuits can be arranged in three configurations
1.Series
2.Parallel
3.Series-Parallel
Resistor configurations

17.
• Two or more components are in series if the head of one connects with
tail of another.
• Image below displays three resistors that join in series to each other.
Series Configuration

18.
• In Numerical analysis you are mostly required to solve all resistors to
simple single resistor.
• To solve resistors in series simply add them:
Series Configuration (continue)

19.
• Two resistors are in parallel when their heads and tails are joined
together.
Parallel Configuration

20.
• To solve parallel resistors the formula used is:
Parallel Resistors (Continue)

21.
• Very often complex circuit contain series-parallel configurations.
• However you can easily solve them if you learn the basic concept.
Series-Parallel

22.
• You need a ohmmeter to measure it practically.
• Connect Ohmmeter in parallel to the resistor and it will display the
value.
How to measure Resistance???

23.
• In numerical problems you can find the resistance provided voltage and
current is given.
• Use Ohm Law for this purpose.
R = V/I
Resistors & Ohm Law

24.
• Guzel Sansilaniz is an Electrical
Educationist, Design Engineer (Siemens)
, Part time teacher (working in a school
(voluntarily) too), student (wow).
• I am learning and I will share all I learn,
• Join my Facebook group or Slide share
account for future updates. Links are all
given. Or simply copy this url in
browser: https://goo.gl/3CUHbH
About Me