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___________?

Related Mcqs:

1. 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...

2. An amplifier using an opamp with slew rate SR=1v/µsec has a gain of 40db.if this amplifier has to faithfully amplify sinusoidal signals from dc to 20 KHz without introducing any slew-rate induced distortion, then the input signal level must not exceed________?

   A. 795mV B. 395mV C. 795 mV D. 39.5mV...

3. Voltage Series feedback also called series-shunt feedback) results in__________?

   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...

4. 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...

5. 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...

6. 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 %...

7. A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by________?

   A. 2 B. 1 C. 1/2 D. 0...

8. A source follower using an FET usually has a voltage gain which is___________?

   A. greater than +100 B. slightly less than unity but positive C. exactly unity but negative D. about -10...

9. 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...

10. Negative feedback in an amplifier____________?

    A. Reduces gain B. Increase frequency &phase distortion C. Reduces bandwidth D. Increases noise...