Question

a wire of length 220 cm is bent to form a circular loop find the area enclosed by the circular loop​

Answer 1

Answer:

Step-by-step explanation:

Solution:

Magnetic field at the centre of the loop

B=u04π.I.2πRR2 ......(i)

For the wire which is looped double let radius becomes r

Then , 12=2πr

or l4π=r

∴B′=μ04π.I.2πr×2r2

Or B′=μ04π.I.l2.2l4π2

Or B′=μ04π.Il×16π2l2 ...(i)

Now, B=μ04π.I.ll2π2R=l2π ...(ii)

Dividing Eq (ii) by Eq. (iii) we get

B′B=μ04π.I.l.16π2l2μ04π.Il.4π2l2

Or B′B=4

Or B′=4B

Solition Image

Answer 2

circumference = 2 π r

220 = 2 * 22/7 * r

220/2 *7/22 = r

35 = r

area = πr²

        = 22/7 * 35²

        = 22/7 * 1225

        = 22 * 175

        = 3850 cm²

HOPE THIS HELPS ^_^