For semi conductor to have negative temperature coefficient of resistance implies that
-
their resistance decrease with temperature
- The resistance increase with temperature
- their resistance is constantly changing with temperature
- they have electrons and holes at high temperature
The correct answer is: 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.