Resistance

How it is used

Symbol R. The resistance of a wire increases with its length and decreases with its cross-sectional area; for most metals it also rises with temperature. Resistances in series simply add. In mechanics, 'air resistance' is another name for drag.

Example sentences

1. The resistance of the filament lamp increases as it gets hotter.

2. Calculate the total resistance of two 10 Ω resistors connected in parallel.

Common collocations

• electrical resistance
• total resistance
• internal resistance
• air resistance
• resistance of a wire

Related terms

• Ohm's lawThe rule that the current through a metal conductor is directly proportional to the voltage across it, as long as its temperature stays the same. It is usually written V = IR.
• voltageThe energy transferred to or by each coulomb of charge between two points in a circuit, also called potential difference. It is measured in volts (V).
• electric currentThe rate at which electric charge flows past a point in a circuit. It is measured in amperes (A), and one ampere is one coulomb of charge per second.
• circuitA closed path through which electric current can flow, made of a power source, wires and components such as lamps, resistors and switches.
• electromotive forceThe energy that a source such as a battery or generator gives to each coulomb of charge passing through it. Despite its name, it is not a force, and it is measured in volts.

This word in other fields

The same English word can have a different meaning in another field:

• resistance · Electrical & Electronics Engineering

More terms: Electricity and Magnetism

• electric charge
• magnetic field
• electric field
• electromagnetic induction
• capacitor