Geo-Scientist Prelims 2023 General Studies Q12: Which one of the following schematic graphs correctly represents…

Which one of the following schematic graphs correctly represents qualitatively the variation of resistivity ρ with respect to temperature T for a semiconductor?

1. (a) ρ rises slowly from a non-zero value, then steeply (curving upward) with T
2. (b) ρ is zero up to a certain T, then jumps and rises linearly
3. (c) ρ rises linearly with T from a non-zero intercept
4. (d) ρ falls steeply and then flattens as T increases