- #1
jawad hussain
- 6
- 1
why resistivity of a metal increases with increase of temperature and conductivity of a semiconductor increases with increase in temperature??
Resistivity is a measure of a material's ability to resist the flow of electric current. It is represented by the Greek letter rho (ρ) and is measured in ohm-meters (Ω·m).
The resistivity of a material is affected by its temperature and composition. Generally, materials with a higher temperature or a higher concentration of impurities have a higher resistivity.
Resistivity and conductivity are inversely related. Conductivity is a measure of a material's ability to conduct electric current, and it is equal to the reciprocal of resistivity (σ = 1/ρ). This means that materials with a high resistivity have a low conductivity, and vice versa.
The unit of conductivity is siemens per meter (S/m). This unit is equivalent to the reciprocal of the ohm-meter (Ω^-1·m^-1) and is used to measure the conductivity of a material.
Resistivity is typically measured using a four-point probe method. This involves passing a known current through the material using two outer probes, while the voltage is measured using two inner probes. The resistivity can then be calculated using Ohm's law (ρ = V/I).