there are two metallic wires of the same thickness made from iron and silver if the length of the iron wire is 12 cmwhat should be the length of the Silver wire which is equal to the resistance of the iron wire
data : resistivity of iron is equal to 10 * 10 ^ - 8 ohmmeter resistivity of silver is equal to 16 * 10 to the power of minus 8 ohm metre
Answers
Answer:
0.075 m.
Explanation:
We know that the formulae of the resistance is given by R=pl/A, where we know that the p being the material's resistivity, resistance is R, cross-sectional area is A and the wire's length is L. The resistance of material is directly proportional to the length L. For different material the values of the resistance and resistivity with length will change.
In the question it is given that the cross-sectional area will be same, so for the two materials if we equate the value of the resistance we will get that (p1)(L1)/A=(p2)(L2)/A.
L2 = р1*L1/p2. So, on substituting the values we will get that (10*10^-8/16*10^-8)-*12. Which on solving we will get the value of the L2 as 0.075 m.
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.