COMEDK · Physics · 21. Magnetic Effects of Current
Two concentric circular coils, each having 10 turns with radii \(0.2 \mathrm{~m}\) and \(0.4 \mathrm{~m}\) carry currents \(0.2 \mathrm{~A}\) and \(0.3 \mathrm{~A}\) respectively in opposite directions. Magnetic field at the centre is
- A \((2 / 3) \mu_{0}\)
- B \((5 / 4) \mu_{0}\)
- C \((1 / 4) \mu_{0}\)
- D \((1 / 6) \mu_{0}\)
Answer & Solution
Correct Answer
(B) \((5 / 4) \mu_{0}\)
Step-by-step Solution
Detailed explanation
The magnetic field at the centre of a circular coil carrying current \(I\) is given by \(B=\frac{\mu_{0} n I}{2 R}\) where, \(n\) = number of turns. For coil \(1, B_{1}=\frac{\mu_{0} \times 10 \times 0.2}{2 \times 0.2}=5 \mu_{0}\) For coil 2,…
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