Question

Please answer Q no 36

Answer 1

Answer:

this question is a very good question which requires thought process

Explanation:

so,

length of the iron wire=12 cm

let the length of the silver wire be x,

resistivity of iron wire = 10×10∧-8 ohm metre

resistivity of silver wire = 16×10∧-8 ohm metre

now, resistance of iron wire = resistance of silver wire

therefore, Ri=Rs

Ri= resistivity×lenght of wire/area of cross-section - equation no. 1

Rs= resistivity×lenght of wire/area of cross-section - equation no. 2

    From equation 1 and 2,

resistivity of iron×length of iron wire/area of iron wire=resistiivity of silver×length of silver wire/area of silver wire

putting values,

10×10^-8×12/A=16×10^-8×length of wire/area

area on both sides will cancel each other out

length of silver wire=10×10^-8×12/16×10^-8

on further solving the equation you will get,

length of silver wire=7.5cm