Resistance: Why Materials Fight the Flow of Electricity

Resistance is how much a material opposes the movement of electrons.
It’s measured in ohms (Ω), named after scientist Georg Ohm.
Good conductors like copper have low resistance, letting current flow easily.
Insulators like rubber or glass have very high resistance, blocking current almost completely.
Resistance turns some electrical energy into heat—like in toasters and space heaters.
Thin or long wires have more resistance than short, thick ones.
Temperature matters—most metals resist more as they heat up.
Ohm’s Law links resistance with voltage and current: 𝑉=𝐼𝑅.
Resistors are tiny components that deliberately add resistance to control circuits.
From glowing light bulbs to slowing currents in electronics, resistance shapes how electricity behaves.