CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2003

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

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

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

    C)  \[\frac{Eqm}{t}\]                            

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

    Correct Answer: D

    Solution :

    Electrostatic force on charged particle                                 \[F=qE\] So, by Newtons law of motion \[F=ma=qE\]      or            \[a=\frac{qE}{m}\] Velocity attained by particle \[v=0+\frac{qE}{m}t\] So, kinetic energy \[K=\frac{1}{2}m{{v}^{2}}\]                 \[K=\frac{1}{2}\frac{m{{q}^{2}}{{E}^{2}}}{{{m}^{2}}}{{t}^{2}}=\frac{{{E}^{2}}{{q}^{2}}{{t}^{2}}}{2m}\]


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