Question

If an electron moves in a circle of radius 21 cm perpendicular to a B field of 0.4 T, what are the speed of the electron and the frequency of motion?

Answer 1

a)

`v = 4.048 *10^6` m/s

b)

Angular frequency =
`1.92 * 10^7`

Step-by-step explanation:

As we know

`v = (qBr)/(m)`

q is the charge on the electron =
`3.2 * 10^(-19)` C

B is the magnetic field in Tesla =
`0.4` T

r is the radius of the circle =
`0.21` m

mass of the electrons =
`6.64 * 10^(-27)` Kg

a)

Substituting the given values in above equation, we get -

`v = (3.2 * 10^(-19)*0.4*0.21)/(6.64 * 10^(-27)) \\v = 4.048 *10^6`m/s

b)

Angular frequency =

`(4.048 * 10^6 )/(0.21) \\1.92 * 10^7`