Question

(a) An electron moves along a circle of radius 1 m in a perpendicular magnetic field of strength 0.50 T. What would be its speed? Is it reasonable? (b) If a proton moves along a circle of the same radius in the same magnetic field, what would be its speed?

Answer 1

The electron’s speed is more than the speed of the light. So, it is not reasonable. (b) The speed of the electron is 5$\times$107 m/s.

Explanation:

In the question, it is given:

(a) Circle’s radius = 1 m

Strength of the magnetic field = 0.50 T

It is known that:

r = meveBeve = rBeme, where me is the electron mass and ve is the electron speed.  

The electron speed moving around the circle is greater than the light’s speed. Thus, it is not reasonable.

(b) For a proton,

r = rBemp,

where mp is the proton’s mass and vp is its speed.

= 5$\times$107 m/s