Question

20. An electron having a charge e moves with a velocity \( v \) in X-direction. An electric field acts on it in Y-direction? The force on the electron acts in (a) positive direction of Y-axis (b) negative direction of \( Y \)-axis (c) positive direction of \( Z \)-axis (d) negative direction of Z-axis

Answer 1

Answer: negative direction of Z-axis

Explanation: 
As electron moving in positive x-direction, so the current  is moving in negative x-direction ( the direction of your middle finger) and the magnetic field acts on positive Y-direction ( the direction of your index finger) then thumb will be in negative Z-direction which is the direction of force.