For semi conductor to have negative temperature coefficient of resistance implies that
-
A.
their resistance decrease with temperature -
B.
The resistance increase with temperature -
C.
their resistance is constantly changing with temperature -
D.
they have electrons and holes at high temperature
Correct Answer: Option A
Explanation
Temperature coefficient of resistance is given by
| α = | Increase in resistance per oC rise in temp. |
| __resistance at 0oC |
And for metals where resistance increase with temperature rise, temperature coefficient of resistance is positive; on the other hand in semi conductors, where resistance decrease with temperature rise, temperature coefficient of resistance is negative.