# Solved Problems-9

Problems-9
In the circuit shown in figure, find out the value of R such that the impedance of the whole circuit should be independent of the frequency of the supply. If voltage = 200 V, L = 0.16 H and C = 100 Î¼F, calculate the power loss in the circuit.

Solution
Impedance of the inductive branch, ZL = (R + jÏ‰L)

Impedance of the capacitive branch,

âˆ´ Impedance of the whole circuit,

In this expression, the imaginary term of the numerator is R times the imaginary term of the denominator. Thus, if the real term i.e.,  is also R times the real term of the denominator i.e. R Ã— 2R, then the term consisting of w will vanish and the impedance will become independent of frequency.

Thus, the condition is,

Putting the value of L and C

Power loss in the circuit,