BHU PMT BHU PMT (Screening) Solved Paper-2010

  • question_answer
    A charged particle of mass m and charge q is released from rest in uniform electric field E. Neglecting the effect of gravity, the kinetic energy of the charged particle after t second is

    A)  \[\frac{E{{q}^{2}}M}{2{{t}^{2}}}\]                           

    B)  \[\frac{2{{E}^{2}}{{t}^{2}}}{mq}\]

    C)  \[\frac{{{E}^{2}}{{q}^{2}}{{t}^{2}}}{2m}\]                            

    D)  \[\frac{Eqt}{t}\]

    Correct Answer: C

    Solution :

                     When charge q is released in uniform electric field E then its acceleration \[a=\frac{qE}{m}\]                                (constant) So, its-motion will be uniformly accelerated motion and its velocity after t second is given by \[v=at=\frac{qE}{m}t\] The KE of charged particle \[KE=\frac{1}{2}m{{v}^{2}}=\frac{1}{2}m{{v}^{2}}=\frac{1}{2}m{{\left( \frac{qE}{m}t \right)}^{2}}\]                                 \[=\frac{{{q}^{2}}{{E}^{2}}{{t}^{2}}}{2m}\]


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