Question

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

Answer 1

Answer:

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}Resistance=ρ

A

l

So,

\begin{lgathered}(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\end{lgathered}

(10×10

−8

)

A

12

=(16×10

−8

)

A

l

l=

16×10

−8

120×10

−8

l=7.5cm

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