Summary Mind map moving charges and magnetism Physics chap: Textbook For Class 12- NEET, JEE

Biot-Savart Law
Formula of Field for straight wire Field Due to bent wire

dB
Idlsin θ B B2 P
r2 P
dl I B1
μ0 Idlsin θ r
dB = θ r
4π r2 )



I P
) θ/2

μ0 magnetic permiability of r β ) θ/2




)
free space or vaccum I
I
μ0= 4π+ 10-7
μ0 I [1+cos θ/2]
In vector form, Btotal=2+ 4π r
1) At point P A sinθ/2
 
 μ0 +
dB = I dl r B is into the plane
4π r3
μ0 I
   B= (sin + sin β ) I
dB is perpendicular to both dl and r using right hand 4π r
screw rule we can find direction of manetic field ) θ/2
B B1 ) θ/2 ) θ/2
2) I I
)
θ/2

Here, B is into the plane F r r
dl
/2
-θ
90


B2




)
r P
θ I
)



μ0 I [1-cos θ/2]
Btotal=2+ 4π r
Examples sinθ/2
  A
 μ I dl+ (-r) I
1) dB = 4π0 P
r3
 
-μ0 I dl+ r r P
= dl
4π r3
 
μ0 I r + dl
= Extend AB downwards and draw a perpendicular from P
4π r3
B



μ0 I (-dl)+ -r 
I
eg: Square eg: Hexagon
2) dB = r P
4π
r 
3
I
-μ0 I dl+ -r l
=
4π r3 I
 
-μ0 I r + dl dl A
=
4π r3 β
I
) )
r


μ0 I l l
 (sin - sin β )

I (-dl)+ (-r)
B=
 μ0 4π r I
3) dB = I
4π r3 P 3) Wire of infinite length
 
μ0 I dl+ r r I
= =90 and β=90 I
4π r3 l
dl l
μ0 I I
B= (sin 90 + sin 90) =900
4π r P
2 2 μ0 I 3 μ0 I
r
μ0 I β=900




MOVING
=
2π r B= B=
πl πl


4) Wire of semi infinite length

μ0 I
B=
4π r
(sin 90 + sin 0 )
Rectangle
μ
= 0I
I
I
4π r Note:-