Question

Two wires of same length and area made of two materials of resistivity p1 and p2 are connected in series to a source of potential V. The equivalent resistivity for the same area is?​

Answer 1

Given that,

Two wires of same length and area.

Resistivity of first wire = ρ₁

Resistivity of second wire = ρ₂

We need to calculate the equivalent resistivity for the same area

Using relation of resistance and resistivity

$R=\dfrac{\rho l}{A}$

If the wire is connected in series

Using formula of series

$R=R_{1}+R_{2}$

Put the value of resistance

$\dfrac{\rho l}{A}=\dfrac{\rho_{1} l}{A}+\dfrac{\rho_{2} l}{A}$

$\dfrac{\rho l}{A}=(\rho_{1}+\rho_{2})\dfrac{l}{A}$

Here, length and area of the wire is same

$\rho=\rho_{1}+\rho_{2}$

Hence, The equivalent resistivity for the same area is $\rho_{1}+\rho_{2}$

(a) is correct option.

Answer 2

Explanation:

a is correct answers

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