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_________?

Related Mcqs:

1. 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

2. 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

3. 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

4. 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

5. 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 %

6. 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

7. Which of the following amplifier circuit using junction transistor has the best gain?

   A. Common base
   B. Common emitter
   C. Common collector
   D. All have the same gain

8. In deriving ac equivalent circuit for an amplifier circuit, we short circuit___________?

   A. all resistors
   B. all transistors
   C. all inductors
   D. all capacitors

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. Generally, the gain of a transistor amplifier falls at high frequencies due to the___________?

    A. Internal Capacitance of the device
    B. Coupling capacitor at the input
    C. Skin effect
    D. Coupling capacitor at the output