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ECE :: Communication Systems

  1. Consider the following test signal patterns

    1. Ramp
    2. Grill
    3. Grey shades
    4. Sine pulse
    5. Picture line up generating equipment
    Which of the above are used in TV studios?

  2. A.
    All
    B.
    1, 2 and 3 only
    C.
    1, 2 and 5 only
    D.
    2, 3, 4 and 5 only

  3. If aspect ratio is and number of lines in each frame is 625, the number of picture elements in one frame is

  4. A.
    x 625
    B.
    (625)2
    C.
    6252
    D.
    (625)2

  5. Indicate the false statement: If SWR on a transmission line is infinite, the line is terminated in

  6. A.
    open circuit
    B.
    short circuit
    C.
    pure reactance
    D.
    complex impedance

  7. In TV signals colour burst is used

  8. A.
    to maintain colour sequence
    B.
    to ensure I and Q phase correctly
    C.
    to synchronise colours
    D.
    for interlacing of horizontal lines

  9. The resonant frequency of an RF amplifier is 1 MHz and its bandwidth is 10 kHz. The Q factor will be

  10. A.
    10
    B.
    100
    C.
    0.01
    D.
    0.1

  11. The total number of pulses in a TV remote control is

  12. A.
    14
    B.
    12
    C.
    10
    D.
    8

  13. Which camera tube has highest sensitivity and very wide spectral response?

  14. A.
    Vidicon
    B.
    Plumbicon
    C.
    New vicon
    D.
    Saticon

  15. Assertion (A): A Smith chart can be used for a number of calculations of a transmission line

    Reason (R): Smith chart is basically a polar impedance diagram.

  16. A.
    Both A and R are correct and R is correct explanation of A
    B.
    Both A and R are correct but R is not correct explanation of A
    C.
    A is correct but R is wrong
    D.
    A is wrong but R is correct

  17. A computer monitor uses 180 W in normal operation and 20 W in sleep mode. The computer is on all the 24 hours but is in sleep mode for 18 hours a days. The energy units saved in 30 days are

  18. A.
    0.54 units
    B.
    86.4 units
    C.
    2.88 units
    D.
    4.8 units

  19. Consider the following functions

    1. It detects the AM video carrier IF so as to produce the video signal
    2. It produces and separates out the inter carrier sound IF of 5.5 MHz
    3. It amplifies the video signal
    4. It amplifies the audio signal
    The video detector in a colour TV performs which of the above functions

  20. A.
    1, 2 and 3
    B.
    1, 2, 3 and 4
    C.
    1 and 2
    D.
    1, 2 and 4