A) \[\frac{m(\pi +4)}{2qB}\]
B) \[\frac{m}{4qB}(\pi +2)\]
C) \[\frac{m}{qB}(\pi +2)\]
D) \[\frac{m}{4qB}(2\pi +3)\]
Correct Answer: A
Solution :
[a] \[R=\frac{mV}{qB}\] \[son\theta =\frac{R}{\sqrt{2}\times R}=\frac{1}{\sqrt{2}},\theta =45{}^\circ \] After coming out of B q will collide with the wall Time to exit B \[{{t}_{1}}=\frac{\pi m}{4qB}\] Time to travel in region where B is absent is \[{{t}_{2}}\] \[\frac{R}{\sqrt{2}s}=\cos 45\] S=R \[{{t}_{2}}=\frac{s}{v}=\frac{R}{V}=\frac{mv}{vqB}=\frac{m}{qB}\] total time \[2{{t}_{2}}=\frac{2m}{qB}\] time for returning journey in B \[{{t}_{3}}=\frac{\pi m}{4qB}\] total time \[=\frac{\pi m}{4qB}+\frac{\pi m}{4qB}+2q\frac{m}{qB}\] \[\frac{m}{qB}\left[ \frac{\pi }{2}+2 \right]=\frac{m}{2qB}[\pi +4]\]You need to login to perform this action.
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