1. Two wires of equal length, one of copper and the other of manganin, have the same resistance. Which wire is thicker??????

Dear Karthika,

Manganin is an alloy of Cu with manganese and nickel. Since the latter two metals have resistivity greater than copper, the pure copper has lower resistivity and the manganin thus has to be thicker to have the same resistance.

Manganin was developed to have a resistivity with lesser dependence on temperature so it''s conceivable that at temperatures sufficiently high, the Cu resistivity would have risen enough to equal that of manganin but at room temperatures the answer stands.

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