JEE Main & Advanced Physics Magnetic Effects of Current / करंट का चुंबकीय प्रभाव JEE PYQ-Magnetic Effects Of Current

  • question_answer
    One of the two small circular coils, (none of them having any self-inductance) is suspended with a V-shaped copper wire, with plane horizontal. The other coil is placed just below the first one with plane horizontal. Both the coils are connected in series with a de supply. The coils are found to attract each other with a force. Which one of the following statements is incorrect? [JEE ONLINE 25-04-2013]

    A) Both the same carry currents in the same direction

    B)             Coils will attract each other, even if the supply is as source.

    C)             Force is proportional to \[{{\operatorname{d}}^{-4}}\], d = distance between the centres of the coils.

    D)             Force is proportional to \[{{\operatorname{d}}^{-2}}\]

    Correct Answer: D

    Solution :

    [d] As the force between the two coils is attractive hence currents in the coil must be in the same direction and the force,\[F\propto \frac{{{I}_{1}}{{I}_{2}}}{2\pi d}\]where \[{{I}_{1}}\]and \[{{I}_{2}}\]are the currents flowing through the coils.


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