First slide

Magnetic field due to a current carrying circular ring

Question

A long wire carries a steady Current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is B. It is then bent into a circular loop of n turns. The magnetic field at the centre of the coil will be

Moderate

A

nB
B

n² B
C

2 n B
D

2n²B

Solution

$B_{centre} = \frac{μ_{0} ni}{2 a}$
or $B = \frac{μ_{0} i}{2 a} (∵ n = 1)$
When the wire is turned into a circular loop of n turns, then radius o becomes (a / n)
$∴ Magnetic field, B_{n} = \frac{μ_{0} ni}{2 (a / n)} = \frac{μ_{0} n^{2} i}{2 a}$
$∴ B_{n} = n^{2} B$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App