Question

there are two metallic wires of the same thickness made of from iron and silver if the length of iron wire is 12 cm what should be the length of silver which is equal to the resistance of iron wire data resistance of iron is equal to 10 into 10 to the power of minus 8 ohm metre resistance of silver is equal to 16 into 10 to the power of minus 8 ohm metre

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,

$Resistance=\rho\frac{l}{A}$

So,

$(10\times 10^{-8})\frac{12}{A}=(16\times 10^{-8})\frac{l}{A}\\l=\frac{120\times 10^{-8}}{16\times 10^{-8}}\\l=7.5\,cm$

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

Answer 2

Sir / Madam How did u take the resistance of silver equal to resistance of iron

Pls give explanation because in the question they have mentioned the length of the silver is equal to resistance of iron

So Im getting confusion pls mention the reason for

Resistance of iron = Resistance of silver