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.