Question

36. There are two metallic wires of the same thickness made from iron
and silver. If the length of iron wire is 12cm what should be the length of
silver wire which is equal to the resistance of iron wire?
Data: Resistivity of iron - 10 X 10 -8 m
Resistivity of silver = 16 X 10 -8 m​

Answer 1

Answer:

L(2) = 0.075 m

Explanation:

R=pl/A

Where R is resistance of a wire, p is the resistivity of a material, l is he length of wire and A is the cross sectional area of a wire. If we equate both equations since the resistance is same for both wires, we will be able to calculate the unknown parameter that is length of the silver wire.

(p1)(L1)/A=(p2)(L2)/A , since area of each wire is same so it will cancel out and we will make L2, subject.

L(2) = $\frac{(p1)(L1)}{(p2)}$

L(2) = 0.075 m.