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ECE :: Communication Systems

  1. In an FM signal, the modulating frequency is 2 kHz and maximum deviation is 10 kHz. The bandwidth requirement is

  2. A.
    2 kHz
    B.
    10 kHz
    C.
    5 kHz
    D.
    32 kHz

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  3. The effective length of antenna is different from actual length due to

  4. A.
    top loading
    B.
    end effects
    C.
    both (a) and (b)
    D.
    none of the above

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  5. In a TV receiver there is no raster, no picture and no sound. The most likely defective stage is

  6. A.
    power supply unit
    B.
    video output circuit
    C.
    horizontal oscillator
    D.
    balun

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  7. Noise can be measured by

  8. A.
    D.C. voltmeter
    B.
    A.C. voltmeter
    C.
    either of the above
    D.
    none of the above

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  9. A 100 + j 100 Ω load is to be matched to a line with Z0 = 300 Ω to give SWR = 1. The reactance of stub is

  10. A.
    j 200 Ω
    B.
    -j 200 Ω
    C.
    j 100 Ω
    D.
    -j 100 Ω

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  11. Assertion (A): For satellites and space probes, PRF of a radar is pretty low.

    Reason (R): PRF of a radar depends on the range of a radar.

  12. 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

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  13. An S/N ratio of 3 expressed in db is

  14. A.
    4.8 dB
    B.
    2.4 dB
    C.
    0.48 dB
    D.
    0.24 dB

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  15. The material used for the magnet of moving coil cone type loudspeaker is

  16. A.
    steel alloy
    B.
    soft iron
    C.
    hard steel
    D.
    Alnico

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  17. CCIR system B employs

  18. A.
    625 lines
    B.
    625 lines with 2 : 1 interlace
    C.
    625 lines with 4 : 1 interlace
    D.
    500 lines with 2 : 1 interlace

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  19. The power to the base unit of a cordless telephone is supplied by

  20. A.
    battery
    B.
    AC mains
    C.
    both battery and AC mains
    D.
    either battery or AC mains

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