Question:
The reactance of an induction coil of 4 H for a dc current (in \( \Omega \)) is:
The reactance of an induction coil of 4 H for a dc current (in \( \Omega \)) is:
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For DC current, the inductive reactance is always zero because the frequency of DC current is zero. The reactance depends on the frequency of the AC current.
Updated On: Apr 7, 2026
- zero
- \( 4\pi \)
- \( 40\pi \)
- \( 400\pi \)
- infinity
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The Correct Option is A
Solution and Explanation
The reactance \( X_L \) of an inductive coil is given by the formula:
\[
X_L = 2\pi f L
\]
Where:
- \( f \) is the frequency of the alternating current,
- \( L \) is the inductance of the coil.
For a DC current, the frequency \( f = 0 \) (because DC current has zero frequency).
Hence, the reactance \( X_L \) for a DC current becomes: \[ X_L = 2\pi \times 0 \times L = 0 \] Therefore, the reactance of the induction coil for a DC current is zero.
- \( L \) is the inductance of the coil.
For a DC current, the frequency \( f = 0 \) (because DC current has zero frequency).
Hence, the reactance \( X_L \) for a DC current becomes: \[ X_L = 2\pi \times 0 \times L = 0 \] Therefore, the reactance of the induction coil for a DC current is zero.
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