Resistors

Heating Effect of Electric Current

The phenomenon where electrical energy is converted into thermal energy as current flows through a conductor, also known as Joule Heating.

Joule’s Law

A principle stating that the amount of heat produced in a conductor is proportional to the square of the current, the resistance of the conductor, and the time the current flows.

H

The symbol representing heat energy produced, measured in joules (J).

I

The symbol representing current, measured in amperes (A).

R

The symbol representing resistance, measured in ohms (Ω).

t

The symbol representing time, measured in seconds (s).

Energy Losses in Power Transmission

Refers to the significant energy losses due to the heating effect of current when electrical power is transmitted over long distances.

Ploss

The symbol representing power losses, which increase with the square of the current.

Resistor

A passive electrical component that limits or regulates the flow of electric current in a circuit.

Fixed Resistors

Resistors with a predetermined resistance value that cannot be changed.

Variable Resistors

Resistors that allow adjustment of resistance, including types like potentiometers, rheostats, and trimmers.

Resistance Value (Ω)

Indicates how much a resistor opposes current flow.

Tolerance (%)

The permissible deviation from the specified resistance value of a resistor.

Power Rating (W)

The maximum power a resistor can dissipate without damage.

Temperature Coefficient

Indicates how resistance changes with temperature.

Color Coding for Resistors

A system using colors to indicate the resistance value, tolerance, and temperature coefficient of resistors.

Resistors in Series

A configuration where the current flowing through each resistor is the same, but the voltage across each may differ; total resistance is the sum of individual resistances.