An electron with kinetic energy 1.40 kev circles in a plane perpendicular to a uniform magnetic field. the orbit radius is 30.0 cm. find (a) the speed of the electron, (no response) m/s (b) the magnetic field, (no response) t (c) the frequency of circling, and (no response) hz (d) the period of the motion.

(a)

(b)

(c)

(d)

Explanation:

Given:

Kinetic Energy of an electron,

radius of the orbit,

we have:

mass of an electron,

charge on an electron,

(a)

we know:

(b)

We also have the relation after the comparison of forces(centripetal and magnetic) on a moving charge in a magnetic field as:

...........................(1)

where:

B = magnetic field normal to the plane of circulating charge

putting respective values in eq. (1)

(d)

angular speed:

∴Time taken for 1 radian:

Now time take for 1 circulation i.e. 2π radians(Time period):

(c)

we know frequency :