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MHT CET · Physics · Electromagnetic Induction

A coil of self-inductance \(L\) is connected in series with a bulb and an a.c. source. Brightness of the bulb decreases when

  1. A an iron rod is inserted in the coil.
  2. B frequency of a.c. source is decreased.
  3. C number of turns in the coil is reduced.
  4. D a capacitance of reactance \(\left(X_C-X_L\right)\) is included in the same circuit.
Verified Solution

Answer & Solution

Correct Answer

(A) an iron rod is inserted in the coil.

Step-by-step Solution

Detailed explanation

\(I = \frac{V}{\sqrt{R^2 + X_L^2}}\) \(X_L = 2\pi f L\)