A coil of self-inductance L is connected in series with a bulb B and an AC source

A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when

Options

(a) number of turns in the coil is reduced
(b) a capacitance of reactance Xc = Xl is included in the same circuit
(c) an iron rod is inserted in the coil
(d) frequency of the AC source is decreased

Correct Answer:

an iron rod is inserted in the coil

Explanation:

By inserting iron rod in the coil, L ↑ z ↑ I ↓ so brightness ↓

admin:

Related Questions

  1. After 300 days, the activity of a radioactive sample is 5000 dps
  2. A proton of mass m and charge q is moving in a plane with kinetic energy E. If there exists
  3. When we hear a sound, we can identify its source from
  4. An air core coil and an electric bulb are connected in series with an AC source.
  5. In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series