Correct Answer - D
(d) The variation of specific resistance with temperature is as follows
`rho = rho_(ref) + [1 + alpha (T - T_(ref))]`
where `rho =` specific resistance with temperature
`rho_(ref) =` specific resistance of reference temperature.
`alpha =` temperature of coefficient of resistance.
Rearranging the terms. we have
`rho = rho_(0) + rho_(0) alpha (T - T_(0))`
On comparing the equation with equation of straight line `y = mx + c`, we have the slope negative.
Note : The temperature coefficient of resistance of semiconductors is negative that is their electrical resistance decrease (or conductivity increases) with rise in temperature. At absolute zero a semicounductor behaves as an ideal insulator
