How does the sign of the phase angle `phi`, by which the supply voltage leads the current in an LCR series circuit, change as the supply frequency is gradually increased from very low to very high values ?

Answer

A

Explanation

The phase angle `(phi)` by which voltage leads the current in L-C-R series circuit is given by
`tan phi = (X_(L)-X_(C))/R = (2pivL-1/(2pivC))/R`
`tan phi lt0` ( for `v lt v_(0)`)
`tan phi gt0` (for `v gt v_(0)`)
`tanphi=0` For `v=v_(0)=1/(2pisqrt(2C))`