Navigate

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 ↓

NEET2013
admin:

Related Questions

  1. If ∆Q>0 when heat flows into a system, ∆W>0 when work is done on the system
  2. The force F acting on a particle of mass m is indicated by the force-time graph
  3. Two bodies of masses m₁ and m₂ are initially at rest at infinite distance apart
  4. The de-broglie wavelength of an electron in 4th orbit is
  5. A step-up transformer operates on a 230 V line and supplies a current of 2 A.