Question

explain which wire will have largaer resistivity and why​

Answer 1

Given:-

• A ( V - I ) graph is given of two wires.
• The two wires of same length and same area.

To Find:-

• Which has greater resistivity.

Formula Used:-

Resistance of a wire is given by;

$\large\red{\underbrace{\underline{\boxed{\green{\tt{\dag R =\rho\dfrac{l}{a}}}}}}}$

Where ,

• R is resistance.
• l is length.
• a is area
• $\rho$ is resistivity.

Answer:

[ For graph refer to attachment : ]

From the graph we can see that the resistance of wire B is greater than the resistance of wire A . Since the slope of line OA is less than the slope of line AB .

If ' R' is the resistance of wire B and 'r 'is the resistance of wire A , then , we can say that:

➥$\tt{ R > r .}$

Now let resistivity of B be $\rho_1$ and of A be $\rho_2$

➥$\tt{\rho_1\dfrac{l}{a}>\rho_2\dfrac{l}{a}}$

➥$\tt{\rho_1 \dfrac{\cancel{l}}{\cancel{a}}\times\dfrac{\cancel{a}}{\cancel{l}}>\rho_2.}$

$\underline{\boxed{\purple{\tt{\underbrace{\overbrace{\leadsto \rho_1>\rho_2.}}}}}}$

Hence the resistivity of wire B is greater than the resistivity of wire A.