Which of the following combinations should be selected for better turning of an LCR circuit used for communication ?

Options

A. `R = 20 Omega, L = 1.5 H, C = 35 mu F`
B. `R = 25 Omega, L = 2.5 H, C = 45 mu F`
C. `R = 15 Omega, L = 3.5 H, C = 30 mu F`
D. `R = 25 Omega, L = 1.5 H, C = 45 mu F`

Answer

C

Explanation

Quality factor (Q) of an L-C-R circuit is given by,
`Q = (1)/(R)sqrt((L)/(C))`
Turning of an L-C-R circuit depends on quality factor of the circuit. Turning will be bettwe when quality factor of the circuit is high.
For Q to be high, R should be low, L should be high and C should be low. Therefore, option (C) is most suitable.