00:01
The kinetic energy of the electron is given to be 1 .01 into 10 to the power of 4 electron volts.
00:09
Here electron volts can be converted to joules by multiplying it with 1 .6 into 10 to the power of minus 19.
00:22
And the magnetic field is given to be 475 gauze which can be converted to tesla by multiplying it with 1 .6 into tesla by multiplying it.
00:34
Width 10 to the power of minus 4.
00:37
And the velocity of the electron is given to be in the south.
00:44
Let us denote south by minus y cap and the magnetic field is directed to the east.
00:55
Let us denote east by x -cap.
01:00
The angle between the velocity and the magnetic field is 90 degrees.
01:07
Now the electron moving in the magnetic field will experience a magnetic force and the magnitude of the magnetic force will provide centipital force for the electron to move in a circular path.
01:26
Here fb can be written as qvb sine theta and fc can be written as mv square over r.
01:37
Now canceling v on both sides and rearranging for r we get mv over qb sine theta...