Electricity

Electric Current

The flow of electric charge, typically electrons, through a conductor.

Electric Circuit

A closed loop that provides a path for electric current to flow.

Formula for Electric Current

I = Q/t, where I is the current measured in amperes, Q is the charge, and t is the time.

Ammeter

A device used to measure the flow rate of electric charge in a circuit.

Electric Potential Difference

The work done to move electric charges against an electric field, measured in volts.

Formula for Electric Potential Difference

V = W/Q, where V is the potential difference, W is work done, and Q is the charge moved.

Voltmeter

A device used to measure the potential difference between two points in a circuit.

Schematic Diagram

A simplified representation of a circuit using symbols to depict components.

Ohm's Law

The principle stating that the current through a conductor is directly proportional to the voltage across it, expressed as V = IR.

Resistance

The opposition to the flow of electric current, measured in ohms (Ω).

Variable Resistance (Rheostat)

A component that adjusts resistance in a circuit to control current flow.

Resistivity

A material property indicating how much that material resists electrical current.

Formula for Resistance

R = ρ l/A, where R is resistance, ρ is resistivity, l is length, and A is cross-sectional area.

Series Circuit

A circuit configuration where resistors are connected end-to-end with the same current flowing through each.

Parallel Circuit

A circuit configuration where resistors are connected across the same two points, allowing current to split.

Joule's Law of Heating

The principle that electrical energy converts into heat when current flows through a resistor.

Formula for Heat Produced

H = I^2Rt, where H is heat, I is current, R is resistance, and t is time.

Electric Power

The rate at which electrical energy is used or converted into other forms of energy.

Units of Power

Power is measured in watts (W) or kilowatts (kW).

Commercial Unit of Energy

Energy used is measured in kilowatt-hours (kWh), which is the energy consumed by a 1 kW appliance running for 1 hour.