A coil of self-inductance `L` is connected in series with a bulb `B` and an `AC` source. Brightness of the bulb decreases whenA. number of turns in the coil is reducedB. a capacitance of reactance `X_(C)=X_(L)` is included in the same circuitC. an iron rod is inserted in the coilD. frequency of the AC source is decreased

A coil of self-inductance `L` is connected in series with a bulb `B` a

1.	A coil of self-inductance `L` is connected in series with a bulb `B` and an `AC` source. Brightness of the bulb decreases whenA. number of turns in the coil is reducedB. a capacitance of reactance `X_(C)=X_(L)` is included in the same circuitC. an iron rod is inserted in the coilD. frequency of the AC source is decreased
Answer» Correct Answer - D When an iron rod is inserted in the coil, then value of `X_(L)` increases (`X_(L)=omegaL=omega(mu_(0)N^(2)A)/(l)`) (`thereforeu` (Peameability of soft iron) gt absolute permeability `(mu_(0))`) In LR series ckt, `I_(V)=(E_(V))/(sqrt(R^(2)+x_(L)^(2)))`

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