posted by sara .
explai biot-savart,law.an electron with velocity 3*107ms1 describe a circular path in a uniform magnetic field of 0.2T,perpendicular to it.calculate the radius of path
The magnetic field B provides the centripetal force to keep it in a circular path.
e V B = m V^2/R
R = mV/(eB)
m and e are the electron mass and charge.
You don't need the Biot Savart Law for this question. There are plenty of good explanations of it online.