BHU PMT BHU PMT (Screening) Solved Paper-2006

  • question_answer
    The magnetic field amplitude of an electromagnetic wave is\[2\times {{10}^{-7}}T\]. Ifs electric field amplitude if the wave is travelling in free space is:

    A)  \[6\,V{{m}^{-1}}\]                         

    B)  \[60\text{ }V{{m}^{-1}}\]

    C)  \[10/6V{{m}^{-1}}\]     

    D)  none of these

    Correct Answer: B

    Solution :

                     We can write the electric and magnetic fields as sinusoidal functions of positions and time t. \[E={{E}_{0}}\sin (kx-\omega t)\] \[B={{B}_{0}}\sin (kx-\omega t)\] In this\[{{E}_{0}}\]and\[{{B}_{0}}\]are the amplitudes of the field. Further,               \[c=\frac{{{E}_{0}}}{{{B}_{0}}}=speed\text{ }of\text{ }light\] or                            \[{{E}_{0}}={{B}_{0}}c\] Given, \[{{B}_{0}}=2\times {{10}^{-7}}T,C=3\times {{10}^{8}}m/s\] \[{{E}_{0}}=2\times {{10}^{-7}}\times 3\times {{10}^{8}}=60\,T\,m/s=6\,V{{m}^{-1}}\]


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