An ionised gas contains both positive and negative ions.

Question

An ionized gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the +x direction and a magnetic field along the +z direction, then

A) Positive ions deflect towards +y direction and negative ions towards -y direction

B) All ions deflect towards +y direction

C) All ions deflect towards -y direction

D) Positive ions deflect towards -y direction and negative ions towards +y direction

Answer 1

Correct Answer: C) All ions deflect towards -y direction

Exaplanation :

As the electric field is switched on, positive ion will start to move along positive x-direction and negative ion along negative x-direction. Current associated with motion of both types of ions is along positive x-direction. According to Fleming's left hand rule force on both types of ions will be along negative y-direction.