question_answer

The region between\[y=0\]and\[y=d\]contains a magnetic field \[\vec{B}=B\overset{\wedge }{\mathop{z}}\,.\] A particle of mass m and charge q enters the region with a velocity \[\vec{v}=v\hat{i}.\] If \[d=\frac{mv}{2qB},\] the acceleration of the charged particle at the point of its emergence at the other side is           [JEE Main 11-Jan-2019 Evening]

A) \[\frac{qvB}{m}\left( \frac{\hat{i}+\hat{j}}{\sqrt{2}} \right)\]

B) \[\frac{qvB}{m}\left( \frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j} \right)\]

C) \[\frac{qvB}{m}\left( \frac{1}{2}\hat{i}-\frac{\sqrt{3}}{2}\hat{j} \right)\]

D) None of these

Correct Answer: D

Solution :

[d]:

As

Acceleration,

*None of the given options is correct.