2. Sample Papers
  3. KVPY

KVPY Sample Paper KVPY Stream-SX Model Paper-3

  • question_answer
    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 \[B\widehat{i}\] exists in the whole space. \[{{P}_{0}}\] is pitch of helix, \[{{R}_{0}}\] is radius of helix).

    A) \[17{{P}_{0}},\]0, \[-\,2{{R}_{0}}\]      

    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 (similarly as in Q.39). 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 .


You need to login to perform this action.
You will be redirected in 3 sec spinner