Question

An electron travels in a circle of radius 6.1 m while under the influence of an unknown magnetic field, directed perpendicular to its velocity. If the particle makes 6.6 trillion complete revolutions per second, determine the magnitude of the magnetic field, in Tesla.

Answer 1

The angular velocity of the particle is given as:

angular velocity = ω = 6.6 trillion revolutions per second

Converting this to linear velocity:

v = 6.6 trillion rev/s * (2*pi/rev) * 6.1 m

v = 25.3*10^19 m/s

The speed of the particle is faster than the speed of light which is about 3*10^8 m/s. No particle can be faster than light, therefore the magnetic field is imaginary.