Home / ECE / Communication Systems :: Section 5

ECE :: Communication Systems

  1. If a line is terminated in characteristic impedance Z0, the input impedance measured at the input will be

  2. A.
    Z0
    B.
    Z0/2
    C.
    Zero
    D.
    infinite

  3. In a TV, the output from RF tuner is about

  4. A.
    1 μV
    B.
    1000 μV
    C.
    100 μV
    D.
    0.5 μV

  5. 24 telephone channels, each band limited to 3.4 kHz, are to be time division multiplexed by using PCM, calculate the bandwidth of PCM system for 128 quantization levels and an 8 KHz sampling frequency

  6. A.
    192 kHz
    B.
    2 MHz
    C.
    1.299 MHz
    D.
    1.54 MHz

  7. A signal is sampled at 8 kHz and is quantized using 8 bit uniform quantizer. Assuming SNRq for a sinusoidal signal, the correct statement for PCM signal with a bit rate of R is

  8. A.
    R = 32 KbPs, SNRq = 25.8 dB
    B.
    R = 64 KbPs, SNRq = 49.8 dB
    C.
    R = 64 KbPs, SNRq = 58.8 dB
    D.
    R = 32 KbPs, SNRq = 49.8 dB

  9. Generally a VCR has

  10. A.
    four stationary video heads
    B.
    two stationary video heads
    C.
    four rotating video heads
    D.
    two rotating video heads

  11. A remote control of TV uses a 10 bit word. The maximum number of total commands it can transmit is

  12. A.
    64
    B.
    256
    C.
    512
    D.
    1024

  13. Telecine equipment in a TV studio consists of

  14. A.
    projector telecine
    B.
    flying spot telecine
    C.
    digital CCD telecine
    D.
    none of the above

  15. TV signal strength when expressed in dB m has the reference of

  16. A.
    10 μV/m
    B.
    5 μV/m
    C.
    2 μV/m
    D.
    1 μV/m

  17. A sinusoidal voltage amplitude modulates a carrier of peak value 5 kV. Each side band has an amplitude of 500 V. The modulation index is

  18. A.
    0.1
    B.
    0.2
    C.
    0.4
    D.
    0.8

  19. Kell factor is about

  20. A.
    5
    B.
    3
    C.
    0.7
    D.
    0.2