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. Laser light is considered to be coherant because it consists of
  2. A cricketer can throw a ball to a maximum horizontal distance of 100 m. With the same
  3. A nucleus disintegrates into two nuclear parts which have their velocities in the ratio
  4. A beam of light of wavelength 600 nm from a distant source falls
  5. If the rise in height of capillary of two tubes is 6.6 cm and 2.2 cm