Weerstand

When a current flows through a circuit, the collisions between electrons and atoms in the wire causes resistance to the electrons' motion, measured in ohms.

A circuit's electrical resistance is the ratio of applied voltage to the current flowing through it. Resistance also depends on the material's resistivity and is equivalent to the resistivity of the material times the length divided by the cross-sectional area of the wire.

Temperature influences the resistance of materials and can be modeled using the resistivity equation.

A component in a circuit that reduces the current flow is known as a resistor, represented by two symbols provided by the American National Standard Institute and the International Electrotechnical Commission.

Carbon is the most common material used to make resistors. The carbon tracks are wrapped around a ceramic core, which is connected to two copper leads and marked with four bands to identify the resistor.

The first two colored bands represent the first two digits of the resistance, while the third and fourth colors represent its multiplier and tolerance.