JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
A square loop of side \(2\, a ,\) and carrying current I, is kept in \(XZ\) plane with its centre at origin. A long wire carrying the same current \(I\) is placed parallel to the \(z-\)axis and passing through the point \((0, b, 0),(b>>a)\). The magnitude of the torque on the loop about \(z-\)axis is given by:
- A \(\frac{2 \mu_{0} I^{2} a^{2}}{\pi b}\)
- B \(\frac{\mu_{0} I^{2} a^{3}}{2 \pi b^{2}}\)
- C \(\frac{\mu_{0} I^{2} a^{2}}{2 \pi b}\)Z
- D \(\frac{2 \mu_{0} I^{2} a^{3}}{\pi b^{2}}\)
Answer & Solution
Correct Answer
(A) \(\frac{2 \mu_{0} I^{2} a^{2}}{\pi b}\)
Step-by-step Solution
Detailed explanation
\(\overrightarrow{\tau}=\overrightarrow{ M } \times \overrightarrow{ B }\) \(=4 a ^{2} I \times \frac{\mu_{0} I }{2 \pi b }\)
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