JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
Two identical circular loops P and Q each of radius r are lying in parallel planes such that they have common axis. The current through P and Q are I and 4I respectively in clockwise direction as seen from O . The net magnetic field at O is:
- A \(\frac{3\mu_{0}I}{4\sqrt{2}r}\) toward P
- B \(\frac{\mu_{0}I}{4\sqrt{2}r}\) toward P
- C \(\frac{\mu_{0}I}{4\sqrt{2}r}\) towards Q
- D \(\frac{3\mu_{0}I}{4\sqrt{2}r}\) towards Q
Answer & Solution
Correct Answer
(D) \(\frac{3\mu_{0}I}{4\sqrt{2}r}\) towards Q
Step-by-step Solution
Detailed explanation
\(B _{ net }= B _1- B _2\) \(=\frac{4 \mu_0 i R^2}{2\left(R^2+R^2\right)^{3 / 2}}-\frac{\mu_0 i R^2}{2\left(R^2+R^2\right)^{3 / 2}}\) \(=\frac{3 \mu_0 i }{4 \sqrt{2} R}\)
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