MCQ
When two magnetic moments are compared using equal distance method the deflections produced are 45 and 30 . If the length of magnets are in the ratio $1: 2$, the ratio of their pole strengths is
  • A
    $3: 1$
  • B
    $3: 2$
  • C
    $\sqrt{3}: 1$
  • $2 \sqrt{3}: 1$

Answer

Correct option: D.
$2 \sqrt{3}: 1$
$ \frac{M_1}{M_2}=\frac{\tan \theta_1}{\tan \theta_2} \Rightarrow \frac{m_1 L_1}{m_2 L_2}=\frac{\tan \theta_1}{\tan \theta_2} $
$ \Rightarrow \frac{m_1}{m_2}=\frac{2}{1} \times \frac{\tan 45^{\circ}}{\tan 30^{\circ}}=\frac{2 \sqrt{3}}{1}$

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