This document discusses resistors, specifically potentiometers and rheostats. It defines a potentiometer as a three-terminal variable resistor that can divide voltage, while a rheostat is a two-terminal variable resistor used to adjust current. The key difference is that a potentiometer has three terminals and divides voltage, whereas a rheostat has two terminals and adjusts current. Examples provided are a television using potentiometers for controls, and a dimmer switch using a rheostat to adjust light intensity.

1. RESISTOR
BY: R.Sharandhass
DixonWongTeck Sin
Huga Sangaran
Christopher Francis Perera
NicholasGanWei Jian

2. CONTENTS
•What is potentiometer?
•What is rheostat?
•Difference between potentiometer and rheostat
•Example of rheostat - Dimmer switch
•Example of potentiometer -Television

3. What is Potentiometer?
•Can be used to allow a change in the resistance in a circuit or as a
variable voltage divider.
•Generally has 3 terminals:
 2 of the terminals are connected to the opposite ends of
a resistive element.
 3rd terminal located in between the other 2 terminals.

5. What is Rheostat?
•Used to control current.
•Able to vary the resistance in a circuit without interruption.
•Uses only two connections
 1st connection > resistive element (wire wound around
core)
 2nd connection > wiper (sliding contact on windings).
•Often used as power control devices
 light intensity, speed of motors, heaters and ovens

7. Difference between Potentiometer and
Rheostat
Potentiometer Difference Rheostat
Three-terminal variable
resistor
Terminal Two-terminal variable resistor
Divides voltage Function Adjusts current
Television Used in Dimmer Switch

8. Example Of Potentiometer:Television
•On-off control - to turn the receiver on or off
•Contrast control - adjust the contrast in the video amplifier
•Brightness control - adjusts the brightness by adjusting DC
voltage on the
control grid
•Channel selection - adjusting programmable dividers

10. Example Of Rheostat: Dimmer Switch
•Lamps can be made brighter or dimmer by rotating or sliding a control
on their switch
•They have rheostat in their switch