Question

Two coplanar concentric circular conductors made of wire of same material and thickness are connected to batteries e1=20v and e2 = 16v. Their radii are r1 = 5 cm and r2 = 10 cm. The resistance of the inner circular conductor is 4 w. Find the magnetic induction at the centre o. If it is n 105 wb/m2 . Find value of n

Answer 1

Answer:

2.4*10^{-5} H

Given:

e1 = 20v

e2 = 16v

r1 = 5cm

r2= 10cm

To Find :

Magnetic induction at the center O .

Solution :

$R_{1} = \frac{p(2\pi *5)}{A}$

= 4 ohm

$R_{1} = \frac{p(2\pi *2*5)}{A}$

= 8 ohm

$I_{1}=\frac{V}{R}$

$=\frac{20}{4}$ = 5A

$I_{2}=\frac{V}{R}$

$=\frac{16}{8}$ = 2A

So ,

$B_{o}=B_{1} + B_{2}$

$=\frac{u_{o}*I_{1} }{2\pi *0.005} + \frac{u_{o}*I_{2}}{2\pi *10*0.0010}$

=$2*10^{5} + 4*10^{-6}$

$2.4*10^{-5} H$