Two identical wires, carrying equal currents are bent into circular coils $A$ and $B$ with 2 and 3 turns respectively. The ratio of the magnetic fields at the centres of the coils $A$ and $B$ is
- A
$4: 9$
- B
$2: 3$
- C
$9: 4$
- D
$3: 2$
✓ Correct answer: A
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