Which of the following combinations should be selected for better tuning of an L-C-R circuit used for communication?
R = 20 , L = 1.5 H, C = 35 F
R = 25 , L = 2.5 H, C = 45 F
R = 15 , L = 3.5 H, C = 30 F
R = 25 , L = 1.5 H, C = 45 F
As we learnt in
Q factor -
- wherein
L - inductance
C - capacitance
Quality factor of L-C-R circuit
Clearly, Q3 is maximum of Q1 , Q2 and Q4
i.e for Q to be high, L should be high and C should be low.
Option 1)
R = 20 , L = 1.5 H, C = 35 F
this is the incorrect option
Option 2)
R = 25 , L = 2.5 H, C = 45 F
this is the incorrect option
Option 3)
R = 15 , L = 3.5 H, C = 30 F
this is the correct option
Option 4)
R = 25 , L = 1.5 H, C = 45 F
this is the incorrect option