KVPY Sample Paper KVPY Stream-SX Model Paper-21

  • question_answer
    The tangent galvanometers having coils of the same radius are connected in series. A current flowing in them produces deflections of \[60{}^\circ \] and \[45{}^\circ \] respectively. The ratio of the number of turns in the coil is:

    A) (4/3)

    B) \[(\sqrt{3}+1)/1\]

    C) \[\left( \frac{\sqrt{3}+1}{\sqrt{3}-1} \right)\]

    D) \[\sqrt{3}/1\]

    Correct Answer: D

    Solution :

    For tangent galvanometer \[\frac{\mu NI}{2R}={{B}_{H}}\tan \theta \]
    \[\therefore \,\,\frac{{{N}_{1}}}{{{N}_{2}}}=\frac{\tan {{\theta }_{1}}}{\tan {{\theta }_{2}}}\Rightarrow \frac{{{N}_{1}}}{{{N}_{2}}}=\frac{\tan 60{}^\circ }{\tan 45{}^\circ }=\frac{\sqrt{3}}{1}\]


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