Electric resistance

The electrical resistance is the opposition to the motion of the electrons through a conductor. It can be said that conductors have low resistance and insulators have very high resistance. This opposition to electric current depends on the type of material, its cross-sectional area, and its temperature. Resistance serves to limit the amount of current through the circuit with a given amount of voltage supplied by a battery or a generator.

When electrons move against the resistance opposition, friction is generated. Just like mechanical friction, the friction produced by electrons flowing against a resistance manifests itself in the form of heat. The concentrated resistance of a lamp’s filament results in a relatively large amount of heat energy dissipated at that filament. This heat energy is enough to cause the filament to glow white-hot, producing light, whereas the wires connecting the lamp to the battery (which have much lower resistance) hardly even get warm while conducting the same amount of current.

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