medium
2 min read
Resistance measure
Resistance Measure Resistance is a measure of the opposition to the flow of an electric current in a circuit. It is represented by the symbol R and m...
Quick Actions
Insights
Difficultymedium
Reading Time2 min
Resistance Measure Resistance is a measure of the opposition to the flow of an electric current in a circuit. It is represented by the symbol R and m...
Resistance is a measure of the opposition to the flow of an electric current in a circuit. It is represented by the symbol R and measured in ohms (Ω).
Key points about resistance:
Resistance is a measure of how much voltage is required to maintain a constant current flow through a circuit.
The higher the resistance, the more voltage is required to power the circuit.
Resistance depends on the type of conductor and the length of the conductor.
In an ideal conductor, the resistance is zero, meaning no voltage drop occurs when current flows through it.
Real-world conductors have non-zero resistance due to factors such as resistance in the conductor itself and contact resistance between the conductor and the measuring device.
Types of resistance:
Ohmic resistance: This is the most basic type of resistance, defined as the ratio of the applied voltage to the current flowing through the conductor.
Non-ohmic resistance: This is a more complex type of resistance that can exhibit non-linearity, meaning the resistance can vary with the applied voltage. This is often seen in real-world conductors, such as carbon and polymer materials.
Examples:
Ohmic resistance: For an ideal conductor with a resistance of 1 Ω, if a voltage of 1 V is applied, the current will be 1 A.
Non-ohmic resistance: For a carbon resistor with a resistance of 10 Ω when a voltage of 1 V is applied, the current will be 0.1 A.
Applications of resistance:
Voltage regulation: Resistance can be used to regulate the voltage of an electrical circuit by controlling the current flowing through it.
Circuit protection: Resistance can be used to protect circuits from damage caused by short circuits or overloads.
Ammeters: Resistance can be used to measure the current flowing through a circuit