Temperature dependence of resistivity p(T) of semiconductors, insulators and metals is significantly based on the following factors:

Options

A. number of charge carries can change with temperature T.
B. time interval between two successive collisions can depend on T.
C. length of material can be a function of T
D. mass of carriers is a function of T.

Answer

A, B

Explanation

As we have the expression, the resistivity for semiconductor and insulator is as follow:
`rho (T) = rho_(0)` exp `((E_(g))/(K_(B)T))`
`E_(g)` = Energy band gap
`K_(B)` = Boltzmann constant
T = Temperature in Kelvin (K)
`rho(T)` = Resistivity at temperature TK
`rho_(0)` = Resistivity at temperature 0 K
Resistivity of metal is given as below
`[rho =(m)/(n e^(2)tau)] and rho (T) = rho_(0) (1 + alpha T)`
m= mass of electron
n = charge carrier density
`tau=` relaxation time
If the temperature changes, the number of charge carriers n and relaxation time `tau` also changes.This is the reason why resistivity varies with temperature. So, option (a) and (b) is correct.