In the plane mirror, the co-ordinates of image after two and half time periods are (initial velocity \[{{V}_{0}}\] is in the xy-plane and the plane mirror is perpendicular to the x-axis. A uniform magnetic field \[B\hat{i}\] exists in the whole space. \[{{P}_{0}}\] is pitch of helix, \[{{R}_{0}}\] is radius of helix). |
A) \[\overrightarrow{c}\]
B) \[3{{P}_{0}},0,-\,2{{R}_{0}}\]
C) \[17.5{{P}_{0}},\,\,0,\,\,-2{{R}_{0}}\]
D) \[3{{P}_{0}},\,\,0,\,\,2{{R}_{0}}\]
Correct Answer: C
Solution :
After two and half time periods, it is at a distance \[2{{R}_{0}}\] on the negative z-axis. Y-coordinate will be zero. And the x-coordinate \[=2.5\,\,{{P}_{0}}.\] i.e. it is at a distance \[7.5\,\,{{P}_{0}}\] from the mirror, hence its image will be at \[2\,\,(7.5\,\,{{P}_{0}})+2.5{{P}_{0}}=17.5\,\,{{P}_{0}}.\] Hence [C].You need to login to perform this action.
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