Electrical Resistance Basics

Resistance is the flow of charge through a material encountering an opposing force similar to mechanical friction.

Resistance is directly proportional to the cross-sectional area of the material.

As the temperature of most conductor and resistive elements increases, the resistance level decreases.

Resistance is determined by the material's resistivity, length, cross-sectional area, and pressure.

Resistance is thus directly proportional to length and inversely proportional to ______

The unit of measurement of resistance is the ampere (A).

The unit of measurement of resistance is the ______ (Ω)

Where ρ (Greek letter rho ) is a characteristic of the material called the ______

At a fixed temperature of 20C (room temp.), the resistance is related to the other three factors by R = ρ -------- (ohms, Ω) ______

As the temperature of most conductor and resistive elements increases, the ______ level increases

Resistance is thus directly proportional to length and inversely proportional to ______

The unit of measurement of resistance is the ______ (Ω)

Where ρ (Greek letter rho ) is a characteristic of the material called the ______

Insulators may break down if subjected to excessive ______

Similarly, conductors may be destroyed if too much ______ is passed through them

The resistance of any conductor can be calculated from a knowledge of it’s cross-sectional area, it’s length, and the ______ of the material

A device constructed to have a certain value of resistance is known as a ______

The power rating of a resistor is important because it limits the maximum voltage that should be applied and the maximum ______ that should flow through the component