An electron enters a region where magnetic (B) and electric (E) f… - Vidyadip

MCQ

An electron enters a region where magnetic $(B)$ and electric $(E)$ fields are mutually perpendicular to one another, then

A
It always possess circular motion
B
It will always move in the direction of $B$
C
It will always move in the direction of $E$
✓
it can go undeflected also

✓

Answer

Correct option: D.

it can go undeflected also

d
when electrons enter in a region where there is only magnetic field, then force exerted by the magnetic field will deflect the electron in a direction perpendicular to its motion and also perpendicular to the magnetic field. Whereas in the presence of electric field, force exerted by the electric field is in a direction opposite to the direction of electric field. As a result, electron deflected by magnetic field is nullified by the deflection by electric field. As a result, electron moves undeflected.

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