Question

there are two nichrome A and B are of equal thickness. Length of A is half to B. Which wire has more resistance and which one will have more resistivity

Answer 1

B wire has more resistance
A wire has more resistivity

Answer 2

Explanation:

Th resistance of a wire is given by :

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

Where,

$\rho$ is the resistivity of the material

l is the length of the wire

A is the area of cross section

It is given that, There are two nichrome wires A and B are of equal thickness. Length of A is half to B.

$R_A=\rho\dfrac{1/2l_B}{A}$.......(1)

$R_B=\rho\dfrac{l_B}{A}$..............(2)

Dividing equation (1) and (2) we get :

$R_B=2\ R_A$

So, the resistance of wire B is more as compared to wire A.

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

As the resistivity is inversely proportional to the length. Hence, the resistivity of wire A is more.