A) opposite to ox
B) along ox
C) opposite to oy
D) along oy
Correct Answer: D
Solution :
According to Maxwell's cork screw rule, the direction of magnetic field at point P in plane of paper is perpendicular to the plane of paper inwards, i.e., along z-direction. Now since charge is moving along x-direction there- fore, from Fleming's left hand rule stretching the forefinger in direction of paper inwards the thumb will indicate the direction of force F acting on the charged particle along oy. Alternative: According to Maxwell's cork screw rule the direction of magnetic field at point P, B acts inwards into plane of the paper, i.e., along z-direction and v is along \[ox\]hence, \[F=Q\left( \vec{v}\times \vec{B} \right)=Q\left| \begin{matrix} {\hat{i}} & {\hat{j}} & {\hat{k}} \\ v & 0 & 0 \\ 0 & 0 & -B \\ \end{matrix} \right|\] \[=Q[\hat{i}(0)-\hat{j}(-vB)+\hat{k}(0)]\] \[=\hat{j}QvB\]You need to login to perform this action.
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