In a parallel resonance circuit formed of L and C, resonance is to be obtained with an oscillator giving an output frequency of ω rad/sec.
To obtain resonance, and unity power factor
(1) either one, L, C or ω can be varied
(2) it is better to vary L rather than C or ω
(3) it is better to vary C or ω rather than L
(4) it is best to vary C
