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ECE :: Electronic Devices and Circuits

  1. The network shown in the figure represents a

  2. A.
    band pass filter
    B.
    low pass filter
    C.
    high pass filter
    D.
    band stop filter

  3. In a bipolar transistor, the emitter base junction has

  4. A.
    forward bias
    B.
    reverse bias
    C.
    zero bias
    D.
    zero or reverse bias

  5. Which of these has semi-conductor metal junction?

  6. A.
    PIN diode
    B.
    Photo diode
    C.
    Tunnel diode
    D.
    Schottky diode

  7. The ripple factor of power supply is a measure of

  8. A.
    its filter efficiency
    B.
    diode rating
    C.
    its voltage regulation
    D.
    purity of power output

  9. Assertion (A): When light falls at junction of p-n photodiode, its p side becomes positive and n side becomes negative.

    Reason (R): When a photodiode is short circuited, the current in the external circuit flows from p side to n side.

  10. A.
    Both A and R are true and R is correct explanation of A
    B.
    Both A and R are true but R is not a correct explanation of A
    C.
    A is true but R is false
    D.
    A is false but R is true

  11. In what condition does BJT act like an open switch

  12. A.
    cut off
    B.
    saturation
    C.
    active
    D.
    both (b) and (c)

  13. In a JFET

  14. A.
    gate source cut off voltage is equal to VDS
    B.
    gate source cut off voltage is equal to pinch off voltage
    C.
    gate source cut off voltage is twice the pinch off voltage
    D.
    gate source cut off voltage is equal to negative pinch off voltage

  15. A power supply has full-load voltage of 20 V. What will be its no load voltage when its voltage regulation is 100%

  16. A.
    0 V
    B.
    10 V
    C.
    20 V
    D.
    40 V

  17. For a photo conductor with equal electron and hole mobilities and perfect ohmic contacts at the ends, an increase in the intensities of optical illumination results in

  18. A.
    change in open circuit voltage
    B.
    change in short circuit current
    C.
    a reduction resistance
    D.
    an increase of resistance

  19. Holes act like

  20. A.
    positive charges
    B.
    neutral atoms
    C.
    negative charges
    D.
    crystals