Question

Define resistivity of the material state its si units discuss the variation of resistivity with temperature in case of metals semiconductors and insulators

Answer 1

• resistivity measure of the resisting power of a specified material to the flow of an electric current.
• its SI unit is ohm metre
• metals metals and alloys have very low resistivity as they are good conductors of electricity whereas insulators are like rubber and glass have high resistivity
• The general rule is resistivity increases with increasing temperature in conductors and decreases with increasing temperature in insulators. ... As temperature rises, the number of phonons increases and with it the likelihood that the electrons and phonons will collide. Thus when temperature goes up, resistance goes up.

Answer 2

  Define resistivity of the material state its

1).  Resistivity :-  It is defined as the resistance offered by a material having cross sectional area one metre square and length of 1 m

2). unit of resistivity is Ohm*Metre

3). for metals , resistivity increases with increasing temperature

4). for insulators , resistivity decrease with increasing temperature

5). for semiconductor , resistivity increase with increase in temp.  for some time until electron of valence band have reached conduction band and then decreases with increase in temperature .