Home / ECE / Analog Electronics :: Section 6

ECE :: Analog Electronics

  1. A voltage tripler circuit and voltage quadrupler circuit use identical components. Then

  2. A.
    voltage regulation in both circuits will be same
    B.
    voltage regulation in both may or may not be same
    C.
    voltage regulation in quadrupler circuit will be better than in tripler circuit
    D.
    voltage regulation in quadrupler circuit will be poorer than in tripler circuit

  3. A Ge diode operated at a junction temperature of 27°C. For a forward current of 10 mA, VD is found to be 0.3 V. If VD = 0.4 V then forward current will be

  4. A.
    400 mA
    B.
    475 mA
    C.
    477 mA
    D.
    480 mA

  5. In a power amplifier the collector current flows for 270° of the input cycle. The operations is

  6. A.
    class A
    B.
    class B
    C.
    class AB
    D.
    class C

  7. An amplifier has input impedance of 4 kΩ and output impedance of 80 kΩ. It is used in negative feedback circuit with 10% feedback. If open loop gain is 90, the closed loop input and output impedances are

  8. A.
    40 kΩ and 8 kΩ respectively
    B.
    4 kΩ and 80 kΩ respectively
    C.
    0.4 kΩ and 800 kΩ respectively
    D.
    8 kΩ and 160 kΩ respectively

  9. In figure the current through resistor R

  10. A.
    is always equal to 130 mA
    B.
    may vary between 130 mA and 10 mA
    C.
    may vary between 65 mA and 10 mA
    D.
    is always equal to 65 mA

  11. In a negative feedback amplifier A = 100, β = 0.04 and Vs = 50 mV, then feedback will be

  12. A.
    4
    B.
    8
    C.
    10
    D.
    2

  13. For an npn transistor connected as shown in the figure VBE = 0.7 volts. Given that reverse saturation current of the junction at room temperature 300K is 10-13A, the emitter current.

  14. A.
    30 mA
    B.
    39 mA
    C.
    49 mA
    D.
    20 mA

  15. The dc output voltage of the circuit is

  16. A.
    4.3 V
    B.
    1.369 V
    C.
    3.87 V
    D.
    1.94 V

  17. A voltage doubler circuit is fed by a voltage Vm sin ωt. The output voltage will be nearly 2 Vm only if

  18. A.
    load resistance is small
    B.
    load resistance is large
    C.
    load resistance is neither small nor large
    D.
    either (a) or (c)

  19. The purpose of connecting a coupling capacitor in the output circuit of an amplifier is

  20. A.
    to increase voltage gain
    B.
    to increase collector current
    C.
    to block dc collector voltage
    D.
    all of the above