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ECE :: Analog Electronics

  1. The voltage gains of an amplifier without feedback and with negative feedback respectively are 100 and 20. The percentage of negative feedback (β) would be

  2. A.
    40%
    B.
    5%
    C.
    20%
    D.
    80%

  3. Figure shows a

  4. A.
    JFET
    B.
    n-channel MOSFET
    C.
    p-channel MOSFET
    D.
    none of the above

  5. Three cascaded stages have gains of 10, 20 and 25. The overall gain will be

  6. A.
    10
    B.
    55
    C.
    500
    D.
    5000

  7. Find the odd one out

  8. A.
    sweep voltage generator
    B.
    multivibrators
    C.
    sine wave oscillators
    D.
    blocking oscillators

  9. The equivalent circuit shown in figure is for

  10. A.
    CE
    B.
    CB
    C.
    CC
    D.
    None of the above

  11. In a one pole active low pass filter, the cut off frequency is fc. Then

  12. A.
    gain decreases at the rate of 20 dB per decade increase in frequency above fc
    B.
    gain decreases at the rate of 20 dB per decade decrease in frequency below fc
    C.
    gain decreases at the rate of 40 dB per decade increase in frequency above fc
    D.
    gain decreases at the rate 40 dB per decade decrease in frequency below fc

  13. Turn off time of a transistor switch is equal to (where ts is storage time and tf is fall time.)

  14. A.
    ts + tf
    B.
    ts - tf
    C.
    2ts
    D.
    2tf

  15. In a CE amplifier circuit the emitter by pass capacitor is remove. The ac output voltage

  16. A.
    increases
    B.
    remains the same
    C.
    increases or decreases
    D.
    decreases

  17. In a differential amplifier, CMRR can be improved by using an increased

  18. A.
    emitter resistance
    B.
    collector resistance
    C.
    power supply voltages
    D.
    source resistance

  19. If ac resistance of diode is re, then In CE, BJT amplifier the input impedance is

  20. A.
    re
    B.
    β re
    C.
    D.
    re)2