Communication systems

The variation of either the amplitude or the frequency of the carrier wave called

• Demodulation

• Modulation

• Bandwidth

• Sideband

For this wave determine the frequency of carrier wave

• 50 Hz

• 10 Hz

• 10 kHz

• 100 kHz

For this wave determine the frequency of the information signal

• 10 kHz

• 5 kHz

• 100 Hz

• 200 kHz

The variation with frequency f of the amplitude A of the transmitted wave is shown in Figure. For this transmission determine the wavelength of the carrier wave

• 33 km

• 30 cm

• 330 mm

• 110 km

The variation with frequency f of the amplitude A of the transmitted wave is shown in Figure. For this transmission determine the bandwidth

• 900 kHz

• 918 kHz

• 18 kHz

• 909 Hz

The variation with frequency f of the amplitude A of the transmitted wave is shown in Figure. For this transmission determine the maximum frequency of the transmitted audiosignal

• 900 kHz

• 9 kHz

• 18 kHz

• 909 Hz

The signal-to-noise ratio at the receiver must not fall below 28 dB. Calculate the minimum input signal power to the receiver

• 0.45mW

• 0.36 $\mu W$

• 0.23 mW

• 0.55 W

The minimum input signal power to the receiver 0.23 mW. What the attenuation in the fibre

• 16 dB

• 25 dB

• 44 dB

• 75 dB

The range of frequencies that the signal occupies is the ...

• Demodulation

• Modulation

• Bandwidth

• Sideband

Upper sideband

• 900 kHz

• 918 kHz

• 18 kHz

• 909 Hz