Quick Answer: What Is The Difference Between A Resistor And A Variable Resistor?

What is a variable resistor called?

A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider.

If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat..

Is a rheostat a variable resistor?

But we can also configure a variable resistor to regulate a current, and this type of configuration is commonly known as a Rheostat. Rheostats are two-terminal variable resistors which are configured to use one end terminal and the wiper terminal only.

What is a resistor at a constant temperature an example of?

A resistor is an electrical component that restricts the flow of electric current. … The current flowing through a resistor at a constant temperature is directly proportional to the potential difference across it. This is called Ohm’s law.

What is an example of a variable resistor?

Variable Resistors are resistors whose resistance values can vary according to some factor applied to them. For example, potentiometers are variable resistors that changes when a user adjusts the knob. Photoresistors are variable resistors which change according to the light that strikes its surface.

Does a resistor obey Ohm’s law?

Ohm’s Law is not a law, per se. It is a description of the relationship of current to voltage for a specific class of electrical objects. … So resistors are not obeying Ohm’s “Law”, rather Ohm’s “Law” is merely a formula for devices which show a constant ratio of voltage to current.

How do resistors affect voltage?

Why does voltage drop across a resistor? It’s because a resistor impedes the amount of charge that flows through it depending on its resistance. This leads to a decrease in current through the circuit. Hence the factor by which voltage is reduced (I*R), and hence current, is called the voltage drop of the resistor.

What does a variable resistor do?

Varying resistance in a circuit will increase or decrease the current. We use this to control other components, for example: Lamps – brighter or dimmer?

What is fixed resistor and variable resistor?

Circuits with LEDs use fixed resistors to limit the current, thus protecting the LED from damage. … A variable resistor, commonly called a potentiometer (pot for short), allows you to adjust the resistance from virtually zero ohms to a factory-determined maximum value.

What is an example of a fixed resistor?

The different types of fixed resistors include: Wire wound resistor. Carbon composition resistor. Carbon film resistor.

What happens when the variable resistor is increased?

If the resistance of a variable resistor is increased, the amount of electric current flows through the resistor decreases. Similarly, if the resistance of a variable resistor is reduced, the amount of electric current flows through the resistor increases.

Is a resistor at a constant temperature linear?

A resistor at constant temperature (ohmic conductor) Plotting a graph of potential difference against current gives a straight line passing through the origin (0,0).

What is the symbol of variable resistance?

Symbolic Representation The variable resistor is represented by a zig-zag line and an arrow across (or above) it, like that shown in the figure below.