An `L-C-R` series circuit with `100Omega` resistance is connected to an `AC` source of `200V` and angular frequency `300rad//s`. When only the capacitance is removed, the current lags behind the voltage by `60^@`. When only the inductance is removed the current leads the voltage by `60^@`. Calculate the current and the power dissipated in the `L-C-R` circuit

Options

A. `2A, 200W`
B. `2 A, 400 W`
C. `4 A, 200W`
D. `4 A, 400W`

Answer

B

Explanation

In `R -L` circuit, `tan 60^(@) = (X_(L))/(R)`
` In `R -C` circuit tan 60^(@) = (X_(L))/(R)`
` X_(L) = X_(C)` case of series resonance)
`I = (V)/(Z) = (V)/ ( R) = (200)/(100) = 2 A`
`P = i^(2) R = (2)^(2) xx 100 =400 W` .