Q: We are given three copper wires of different lengths and different areas of cross-section. Which one of the following would have highest resistivity?
(a)Copper wire of 50 cm length and 1 mm diameter
(b)Copper wire of 25 cm length and 0·5 mm diameter
(c)Copper wire of 10 cm length and 2·0 mm diameter
(d)All the wires would have same resistivity
Correct Answer: (c)
Detailed explanation coming soon.