Resistance

Resistance Resistance is a measure of the opposition to the flow of electric current. The symbol used is R, and the unit is Ohm (Ω). 1Ω equals the resistance when 1V of voltage is applied and produces a current of 1A. Resistance, R, is proportional to the lead length (L) and inversely proportional to the cross sectional area (A). Hence, when the lead length is long, as the length of the pathway for the current to travel through is longer, the resistance also increases. When the cross sectional area is bigger, current can move more easily, decreasing resistance. The relationship between lead length, cross sectional area, and lead length in an equation is R =ρ L /A. The proportional constant, ρ, is the matter’s unique value. This is the resistivity. ※ The equation for electric resistivity