In a CB amplifier the maximum efficiency could be____________?

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. 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. The bandwidth of an RF tuned amplifier is dependent on____________?

   A. Q –factor of the tuned o/p circuit
   B. Q –factor of the tuned i/p circuit
   C. Quiescent operating point
   D. Q-factor of the o/p and i/p circuits as well as quiescent operating point

4. A change in the value of the emitter resistance Re in a differential amplifier?

   A. affects the difference mode gain Ad
   B. affects the common mode gain Ac
   C.affects both Ad and Ac
   D. does not effect either Ad and Ac

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

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

6. Most of the linear ICs are based on the two-transistor differential amplifier because of its___________?

   A. input voltage dependent linear transfer characteristic
   B. high voltage gain
   C. high input resistance
   D. high CMRR

7. 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

8. 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

9. 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

10. 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