Question

Which one of the following schematic curves best represents the variation of conductivity \( \sigma \) of a metal with temperature \( T \)? 

Hint:

In metals, the conductivity typically decreases with increasing temperature due to increased scattering of conduction electrons.

Answer 1

Step 1: Understanding the relationship between conductivity and temperature.
In most metals, as temperature increases, the conductivity decreases due to increased lattice vibrations which scatter electrons. This results in a negative temperature coefficient of resistance. The graph that best represents this relationship is a decreasing curve, corresponding to option (A).
Step 2: Conclusion.
Thus, the correct answer is option (A) because conductivity decreases with increasing temperature in metals.