Question

If length is 1/3 and area is 3a then what will be new resistance

Answer 1

Correct Question :

If lenght is ${\sf \dfrac{\ell}{3}}$ and area is 3a then what will be new resistance.

Given :

• New Resistance length = ${\sf \dfrac{\ell}{3}}$
• Area of new Resistance = 3a

To Find :

• New Resistance ${\sf ( R_2)}$

Formula Used :

$\implies\underline{\boxed{\sf R= \rho \dfrac{\ell}{A}}}$

Solution :

Let , old resistance = ${\sf R_1}$

$\implies{\sf R_1 = \rho \dfrac{\ell}{a} }$

New Resistance ,

$\implies{\sf R_2 = \rho \dfrac{\ell}{3 \times 3a}}$

$\implies{\sf R_2= \dfrac{1}{9}\times \rho \dfrac{\ell}{a} }$

$\implies{\bf R_2=\dfrac{R_1}{9} }$

Answer :

New Resistance is ${\bf \dfrac{R_1}{9}}$