Question

please solve it fast​

Answer 1

Answer:

• =$\frac{3}{2}$

Explanation:

Wire A

Length= l

radius= r

=> Area= $\pi r ^2$

Wire B

Length= l` = 2 l

radius = r` = 2 r

=> Area= $\pi r`^2=\pi(2r)^2=4 \pi r^2$

Now, using these information below :

Resistance of series combination= $R_{1}+R_{2}$

$=\frac{\rho l}{\pi r^2} + \frac{\rho 2l}{4\pi r^2}\\\\=\frac{2(\rho l)+\rho l}{2 \pi r^2}=\frac{3\rho l}{2 \pi r^2}.................(i)\\\\\\Now, Resistance\;of\;wire\;A\\=\frac{\rho l}{\pi r^2}.........(ii)$

Now, it is asked that

to find

$\frac{Resistance\;of\;series\;combination}{Resistance\;of\;wire\;A}$

So,

$\frac{Resistance\;of\;series\;combination}{Resistance\;of\;wire\;A}=\frac{(i)}{(ii)}\\\\=\frac{\frac{3\rho l}{2\pi r^2} }{\frac{\rho l}{\pi r^2}}=\frac{3}{2}\\\\\\Learning\;\;together\;:)$