Answer:
Magnetic field, 
Explanation:
Given that,
Velocity of electron, 
It enters a region of space where perpendicular electric and a magnetic fields are present.
Magnitude of electric field, 
We need to find the magnetic field will allow the electron to go through the region without being deflected.
Magnetic force on the electron,
.......(1)
Electric force on the electron, F = q E........(2)
From equation (1) and (2) we get:



B = 0.0002 T
or

Hence, this is the required solution.
Answer:
Radius, 
Explanation:
It is given that,
Magnetic field, B = 0.275 T
Kinetic energy of the electron, 
Kinetic energy is given by :


v = 1037749.04 m/s
The centripetal force is balanced by the magnetic force as :




So, the radius of the circular path is
. Hence, this is the required solution.
Answer:
The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection.