Physics Times 07.2019

3. 
   

0

4

B i

d







(III) For axial position of wire:

Magnetic induction at the centre of current

carrying wire bent in the form of square of

side ‘a’ is

8 2^0

4

B i

a





  

 

 



B due to current carrying circular Coil

Magnetic Induction on the axis of a circular current

carrying coil is :

 

2

0

2 2 3

2 2

B niR

R x

 



Where n is the number of turns, 'R' is the radius

of the coil and 'x' is the distance of the point from

the centre of the coil.

Case-1: At the center of coil (x=0) B =^0

2

ni

R



Case-2 : If x>> R then

2

2 3

B oniR

x





4. Magnetic Moment of a current loop

 i R n^2 ˆ

Where nˆ is Perpendicular to the plane of the

loop

Magnetic moment of a rotating point charge:

2

iA q ( r )^2 q r

2 2

     



(i)

5. Relation between L and

7.



(^2)
q L
m
  
 

6. Ampere's Law (Circuital Law)
   The line integral of B dl.



around any closed path

is equal to  0 times the net current across the area

bounded by this path



3. due to current carrying circular Coil


4. Magnetic Moment of a current loop
   5. Relation between L and
   6. Ampere's Law (Circuital Law)
   7. due to solid cylindrical conduting wire

B l. d ^0 i





with respect to the above fig.

i i i i   1 2 3



B due to solid cylindrical conduting wire

Consider a cylindrical wire carrying current i 0