Q.

In an LCR series circuit, an inductor 30 mH and a resistor 1 Ω are connected to an AC source of angular frequency 300 rad/s. The value of capacitance for which the current leads the voltage by 45° is 1x×10-3 F. Then the value of x is _______.


Ans.

(3)

tanϕ=xC-xLR

tan45°=xC-xLR

xC-xL=R

1ωC-ωL=R

1ωC-300×0.03=1

1ωC=10

C=110ω=110×300

C=13×10-3

x=3