Question

In an LCR series circuit the capacitance is changed from `C` to `4C` For the same resonant fequency the inductance should be changed from `L` to .
A. L/4
B. L/2
C. L
D. 2L

Answer 1

Correct Answer - A
`f=(1)/(2pisqrt(LC))`
For resonant frequency LC is constant
`therefore LC=L_(1)C_(1)`
`therefore L_(1)=(C)/(C_(1))L=(L)/(4)`