Alternating Current

For an L-C-R circuit the impedance (Z) is given by

Z =
where
and
Given, f = ,
and C = 20 C

Z =
Z =
Hence, current in circuit is given by
i =
= 0.1 A
Voltage across capacitor is,

=

Answer (b) at high voltage and high current

In an AC circuit, the coil of high inductance and negligible resistance used to control current, is called the choke coil. The power factor of such a coil is given by $ (as\,R<