A. Increase in both input & output impedances
B. Decreases in both input & output impedances
C. Increase in input impedance & decreases in output impedance
D. Decrease in input impedance & increase in output impedance
Related Mcqs:
- An amplifier without feedback has a voltage gain of 50,input resistance os 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is___________?
A. 1/11KΩ
B. 1/5KΩ
C. 5KΩ
D. 11KΩ - A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are_____________?
A. 5 Ω & 20 %
B. 25 Ω & 20 %
C. 5 Ω & 16.7 %
D. 25 Ω & 16.7 % - In the differential voltage gain & the common mode voltage gain of a differential amplifier are 48db &2db respectively, then its common mode rejection ratio is__________?
A. 23dB
B. 25dB
C. 46dB
D. 50dB - Three identical amplifiers with each one having a voltage gain of 50,input resistance of 1KΩ & output resistance of 250 ,are cascaded.The open circuit voltage gain of combined amplifier is_________?
A. 49dB
B. 51dB
C. 98dB
D. 102dB - An OPAMP has a slew rate of 5 V/μ S .The largest sine wave O/P voltage possible at a frequency of 1 MHZ is [Hint: Slew rate is defined as the max. rate of change of output voltage. Its unit is V/μS.
A. 10 volts
B. 5 volts
C. 5/1 volts
D. 5/2 volts - In a full-wave rectifier using two ideal diodes,Vdc & Vm are the dc & peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is____________?
A. Vdc = Vm/π, PIV=2Vm
B. Vdc = 2Vm/π, PIV=2vm
C. Vdc = 2Vm/π, PIV=Vm
D. Vdc = Vm/π, PIV=Vm - Negative feedback in an amplifier____________?
A. Reduces gain
B. Increase frequency &phase distortion
C. Reduces bandwidth
D. Increases noise - A constant current signal across a parallel RLC circuits gives an o/p of 1.4v at the signal frequency of 3.89KHZ and 4.1KHZ .At the frequency of 4KHZ,the o/p voltage will be___________?
A. 1 v
B. 2v
C. 1.4v
D. 2.8v - A 741-type OP-AMP has a gain-bandwidth product of 1MHz. A non-inverting amplifier using this op-amp & having a voltage gain of 20db will exhibit -3db bandwidth of__________?
A. 50 KHz
B. 100KHz
C. 1000/17 KHz
D. 1000/7.07 KHz - An n- channel JFET has IDSS=2mA,and Vp=-4v.Its transconductance gm=in mA/V)for an applied gate to source voltage VGS=-2v is___________?
A. 0.25
B. 0.5
C. 0.75
D. 1