NEET-XII-Physics

39: Alternating Current

with Solutions - page 3
Qstn# iii-3 Prvs-QstnNext-Qstn
  • #3
    In an AC series circuit, the instantaneous current is zero when the instantaneous voltage is maximum. Connected to the source may be a
    (a) pure inductor
    (b) pure capacitor
    (c) pure resistor
    (d) combination of an inductor and a capacitor
    digAnsr:   a,b,d
    Ans : (a) pure inductor
    (b) pure capacitor
    (d) combination of an inductor and a capacitor.
    For a pure inductive circuit, voltage leads the current by `` 90°``. So, the instantaneous current is zero when the instantaneous voltage is maximum.
    Similar is the case with a purely capacitive circuit, in which, current leads the voltage by `` 90°``.
    Also, in a circuit containing a combination of inductor and capacitor, the current may lead or lag the voltage by `` 90°``, depending upon whether the voltage across the inductor or the capacitor is greater. Here too, there is a phase difference of `` 90°`` between the voltage and current. Hence, the the instantaneous current is zero when the instantaneous voltage is maximum.
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