write biot-Savarts law?????????????
Answers
A current element is a conductor carrying current.It is the product of current,I and length of very small segment of current carrying wire ,dL.
Let us consider a small element AB of length dl of the conductor RS carrying a current I.
Let r be the position vector of the point P from the current element I dL.and θ be the angle dl and r.
According to Biot-Savarts law,the magnetic field induction dB or magnetic flux density at a point P due to current element depends upon the following factors.
(i) dBI
(ii) dBdl
(iii) dBsinθ
(iv) dB1/r^2
Combining these factors,we get
dBIdLsinθ/r^2
or dB=K Idl sinθ/r^2
where K is a constant of perportionality.
In S.I units, K=μ0/4
thus , dB=μ0/4 I dl sinθ/r^2
where μ0 is absolute premeability of free space and
μ0=4*10^-7 Wb A^-1m^-1
= 4*10^-7*TA^-1m [ 1T=1 Wb m^-2]
In C.G.S units,K=1 (In free space)
Thus dB=Idl sinθ/r^2
In vector form,
dB=μ0/4 I(dl*r)/r^3
magnetic field induction at point P due to current through entire wire is
B=∫μ0/4Idl*r/r^3
Or B=∫μ0/4 Idl sin θ/r^2
Biot Savart Law
- Directly proportional to current (I)
- Directly proportional to the length of the element (dl)
- Directly proportional to the sine of angle θ between the direction of current and the line joining the element dl from point A.
- Inversely proportional to the square of the distance (x) of point A from the element dl.