Passive Filters - Engineering

Q1:

A series resonant band-stop filter consists of a 68  resistor, a 110 mH coil, and a 0.02 F capacitor. The internal resistance, RW, of the coil is 4 . Input voltage is 200 mV. Output voltage is taken across the coil and capacitor in series. What is the output voltage magnitude at f0?

A 1.1 mV

B 11.1 mV

C 111 mV

D 200 mV

ANS:B - 11.1 mV

Since at Resonance XL = XC,

Therefore By Voltage Divider Rule,

Vo = Vi*[Rl/(Rl+R)].

= 0.2*[4/(68+4)].

= 11.1 mV.