Electric Current

Electric current is defined as

Electric current is defined as the rate of flow of electric charge through any cross-section of a conductor. If a charge ΔQ flows through a surface in

Ohm's Law (1828) states that

Ohm's Law (1828) states that the electric current through a conductor is directly proportional to the potential difference applied across it, provided

Experiments show that resistance of

Experiments show that resistance of a conductor is: (1) directly proportional to its length l: R ∝ l, and (2) inversely proportional to its cross-sect

Carbon resistors use a standard colour

Carbon resistors use a standard colour code system to indicate their resistance values. Four coloured bands are printed on the resistor body: Band 1 (

For most metals

For most metals, resistivity increases linearly with temperature over a limited range: ρ = ρ₀[1 + α(T - T₀)], where ρ₀ = resistivity at reference temp