JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
One of the two identical conducing wires of length \(L\) is bent in the form of a circular loop and the other one into a circular coil of \(N\) identical turns. If the same current is passed in both, the ratio of the magnetic field at the central of the loop \((B_L)\) to that at the centre of the coil \((B_C),\); \(.\,\frac {B_L}{B_C}\) will be
- A \(N\)
- B \(\frac {1}{N}\)
- C \(N^2\)
- D \(\frac {1}{N^2}\)
Answer & Solution
Correct Answer
(D) \(\frac {1}{N^2}\)
Step-by-step Solution
Detailed explanation
\(B_{L}=\frac{\mu_{0} i}{2 R}\) \(B_{C}=\frac{\mu_{0} N i}{2(R / N)}\) \(\therefore \quad \frac{B_{L}}{B_{C}}=\frac{1}{N^{2}}\)
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