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?
Resistivity of iron 10 X 10 -8 92m
Electridy
Resistivity of silver = 16 X 10 -8 m​

Answer 1

Answer:

Length = 7.5 cm

Explanation:

In the question,

Length of the Iron wire = 12 cm

Resistance of Iron wire = Resistance of Silver Wire

Also,

Area of cross section, A of Iron wire = Area of cross section of Silver wire

Resistivity of Iron = 10 x 10⁻⁸ Ωm

Resistivity of Silver = 16 x 10⁻⁸ Ωm

So,

We know that the Resistance of the wire is given by,

So,

Therefore, the length of the Silver wire is 7.5 cm.