An ionized gas contains both +ve and -ve ions which are initially at rest. The gas is subjected to `vecE` toward positive x-axis, magnetic field along +ve z axis. Then.find the direction of deflection of
a) +ve charged ions b) -ve charged ions

Explanation

`vecF=q(vecvxxvecB)`
In case of +ve charged ions, direction of `vecF=+(hatixxhatk)`
(`vecV` direction is same as `vecE`)=`-hatj`
i.e +ve charged ions deflect towards -ve y-axis
in case of -ve charged ions direction of `vecF`
`=-(-hatixxhatk)` (`becausevecV` direction is opp to `vecE`) =`-hatj`
i.e -ve charged ions also deflect towards -ve y-axis