Question

Solve this question.... ......​

Answer 1

$\huge\underline{\underline{\bf \orange{Question-}}}$

A piece of wire of resistance 20Ω is drawn out so that its lenght is increased to twice of its original lenght . Calculate the resistance of the wire is the new situation .

$\huge\underline{\underline{\bf \orange{Solution-}}}$

$\large\underline{\underline{\sf Given:}}$

• Resistance ${\sf (R_1)}$ = 20Ω
• Lenght = L
• New Lenght = 2L

$\large\underline{\underline{\sf To\:Find:}}$

• New Resistance ${\sf (R_2)}$

We know that ,

✪$\large{\boxed{\bf \blue{R=\rho\dfrac{L}{A}} }}$

$\implies{\sf R_1=\dfrac{L}{A} }$

$\implies{\sf R_2=\dfrac{2L}{\dfrac{A}{2}} }$

$\implies{\sf R_2=4×\dfrac{L}{A}}$

$\implies{\sf R_2=4×R_1 }$

$\implies{\sf R_2=4×20 }$

$\implies{\bf\red{New\: Resistance ( R_2)=80\:Ω}}$

$\huge\underline{\underline{\bf \orange{Answer-}}}$

New Resistance ${\bf \red{80Ω}}$