Moving charges and magnetism

Biot-Savart Law

  • According to Biot savarts law the magnitude of the intensity of magnetic field due to a smell element “dl” is \tt dB = \frac{\mu_{o}}{4 \pi } \frac{i d l \sin \theta}{r^{2}}
  • The magnetic field due to entire conductor is given by \tt B = \frac{\mu_{o}}{4 \pi} \int \frac{d l \sin \theta}{r^{2}} 
  • The magnetic field at a point on the axis of coil when \tt B = \frac{\mu_{o} n i r^{2}}{2 (r^{2} + x^{2})^{3/2}} where, r = radius x = distance
  • The magnetic field on the axis of the coil when π >>>> r\tt B = \frac{\mu_{o} n i r^{2}}{2 x^{3}} = \frac{\mu_{o}}{4 \pi} \left(\frac{2 n i \pi r^{2}}{x^{3}}\right)
  • If current in the loop is anti-clock wise it acts as a North Pole

  • If current in the loop is clock wise it acts as a South Pole

View the Topic in this video From 29:29 To 40:33

Disclaimer: may from time to time provide links to third party Internet sites under their respective fair use policy and it may from time to time provide materials from such third parties on this website. These third party sites and any third party materials are provided for viewers convenience and for non-commercial educational purpose only. Compete does not operate or control in any respect any information, products or services available on these third party sites. makes no representations whatsoever concerning the content of these sites and the fact that has provided a link to such sites is NOT an endorsement, authorization, sponsorship, or affiliation by with respect to such sites, its services, the products displayed, its owners, or its providers.

1. Biot-Savart Law
|d\overrightarrow{B}| = \frac{\mu_{0}}{4 \pi}\frac{Idl \sin \theta}{r^{2}}

2. If the circular loop has N turns then magnetic field strength at its centre is B = \frac{\mu_{0}NI}{2r} and at any point on the axis of circular loop is B = \frac{\mu_{0}Nlr^{2}}{2(r^{2} + x^{2})^{3/2}}