Menu
Home / ECE / Communication Systems :: Section 8

ECE :: Communication Systems

Communication Systems - Section 1
Communication Systems - Section 2
Communication Systems - Section 3
Communication Systems - Section 4
Communication Systems - Section 5
Communication Systems - Section 6
Communication Systems - Section 7
Communication Systems - Section 8
Communication Systems - Section 9
Communication Systems - Section 10
Communication Systems - Section 11
Communication Systems - Section 12
Communication Systems - Section 13
Communication Systems - Section 14
Communication Systems - Section 15
Communication Systems - Section 16
Communication Systems - Section 17
Communication Systems - Section 18
Communication Systems - Section 19
Communication Systems - Section 20
Communication Systems - Section 21
Communication Systems - Section 22
Communication Systems - Section 23
Communication Systems - Section 24
Communication Systems - Section 25
Communication Systems - section-26
Communication Systems - Section-27

  1. In a satellite system circular polarization is to be obtained. The antenna used is

    2. A.
    parabolic
    B.
    horn
    C.
    log periodic
    D.
    helical

    View Answer

    Workspace

    Discuss Discuss in Forum

  2. A horizontal output stage is cutoff for retrace and 40% of trace. If time for each horizontal line is 64 μs and retrace time is 12 μs, the transistor is conducting for about

    3. A.
    64 μs
    B.
    6.4 μs
    C.
    31 μs
    D.
    3.1 μs

    View Answer

    Workspace

    Discuss Discuss in Forum

  3. A TV remote control works on the principle of

    4. A.
    pulse code modulated ultra violet light
    B.
    pulse code modulated infrared light
    C.
    demodulation
    D.
    either (a) or (b)

    View Answer

    Workspace

    Discuss Discuss in Forum

  4. As the magnitude of reverse bias is increased, the capacitance of varactor diode

    5. A.
    increases
    B.
    decreases
    C.
    first increase, then decreases
    D.
    first decreases then increases

    View Answer

    Workspace

    Discuss Discuss in Forum

  5. To prevent overloading in the last IF amplifier one should use

    6. A.
    variable sensitivity
    B.
    squelch
    C.
    double conversion
    D.
    variable selectivity

    View Answer

    Workspace

    Discuss Discuss in Forum

  6. Push pull amplifier is

    7. A.
    class B
    B.
    class A
    C.
    class C
    D.
    Class A or Class C

    View Answer

    Workspace

    Discuss Discuss in Forum

  7. The tape recorders used in homes have

    8. A.
    common head and common amplifier system for recording and playback
    B.
    different heads and amplifiers for recording and playback
    C.
    same head but different amplifiers for recording and playback
    D.
    different heads but same amplifier for recording and playback

    View Answer

    Workspace

    Discuss Discuss in Forum

  8. In a communication system, noise is most likely to affect the signal

    9. A.
    at the receiver
    B.
    at the transmitter
    C.
    at the information source
    D.
    in the channel

    View Answer

    Workspace

    Discuss Discuss in Forum

  9. Each frequency in the modulating wave gives rise to four side bands.

    10. A.
    True
    B.
    False

    View Answer

    Workspace

    Discuss Discuss in Forum

  10. Assertion (A): CCIR-B system has 625 scanning lines per frame and 2 : 1 interlace.

    Reason (R): The aspect ratio is 4 : 3

    11. 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

    View Answer

    Workspace

    Discuss Discuss in Forum

Java Programming Questions and Answers Interview Questions and Answers