Q18 of 51 Page 330

Figure shows a typical circuit for low-pass filter. An AC input Vi = 10 mV is applied at the left end and the output V0 is received at the right end. Find the output voltages for v = 10 kHz, 100 k Hz, 1.0 MHz and 10.0 MHz Note that as the frequency is increased the output decreases and hence the name low-pass filter.


Given: Voltage V1=10×10-3V,


Resistance (R) =1×103 ohm,


Capacitance (C) =10×10-9 F


Angular velocity will be



{a} At frequency (f) =10kHz


Reactance,





Impedance,




Then, Current (I0) will be




Thus, Output voltage (V0) will be





{b} At frequency (f) =100kHz


Reactance,





Impedance,




Then, Current (I0) will be




Thus, Output voltage (V0) will be





{c} At frequency (f) =1 MHz


Reactance,





Impedance,




Then, Current (I0) will be




Thus, Output voltage (V0) will be





{a} At frequency (f) =10 MHz


Reactance,





Impedance,




Then, Current (I0) will be




Thus, Output voltage (V0) will be





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