Force on Current-Carrying Conductors
One of the two small circular coils, (none of them having any self-inductance) is suspended with a V-shaped copper wire, with plane horizontal. The other coil is placed just below the first one with plane horizontal. Both the coils are connected in series with a dc supply. The coils are found to attract each other with a force. Which one of the following statements is incorrect?
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Answer: (d)
- Coils in series attract, so their currents are in the same direction: (a) correct.
- With ac both currents reverse together, so they stay parallel and still attract: (b) correct.
- The coils are very close ( radius), so they behave like two parallel wires: , (c) correct and (d) incorrect.
- So the incorrect statement is (d).