NEET-XII-Physics

39: Alternating Current

with Solutions - page 4
Qstn# iv-17 Prvs-QstnNext-Qstn
  • #17
    An inductor-coil, a capacitor and an AC source of rms voltage 24 V are connected in series. When the frequency of the source is varied, a maximum rms current of 6.0 A is observed. If this inductor coil is connected to a battery of emf 12 V and internal resistance 4.0 Ω, what will be the current?
    Ans : RMS value of voltage, Erms = 24 V
    Internal resistance of battery, r = 4 Ω
    RMS value of current, Irms = 6 A
    Reactance `` \left(R\right)`` is given by,
    `` R=\frac{E}{{I}_{\,\mathrm{\,rms\,}}}``
    `` \Rightarrow R=\frac{24}{6}=4\,\mathrm{\,\Omega \,}``
    Let R' be the total resistance of the circuit. Then,
    R' = R + r
    `` \Rightarrow `` R' = 4 Ω + 4 Ω
    `` \Rightarrow ``R' = 8 Ω
    Current, I = `` \frac{12}{8}\,\mathrm{\,A\,}``
    = 1.5 A
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