Q24: What is the signal to noise ratio of a communications system if the signal is...

Transcribed Image Text:

Q24: What is the signal to noise ratio of a communications system if the signal is 5 V and the noise is 5 mV (5 x 10 V)? (c) - 10 dB (d) + 30 dB (e) - 30 dB (a) - 60 dB a. O b. O c. d. e. QUESTION 27 QUESTION 25 Q25: What is the signal to noise ratio of a communications system if the signal is 5 W and the noise is 5 mW (5 x 10- W)? (a) + 60 dB (d) + 30 dB (e) - 60 dB b. O c. O d. e. (b) + 60 dB e. (b)- 30 dB QUESTION 26 Q26: In all communications systems all the devices and subsystems used add noise to the signals being transmitted through them. The output power of a receiver in the presence of a signal is 50 mW, while the output noise (i.e. output without a signal present) is 500 W. The signal to noise ratio is: (a) 100 dB (b) 25 dB (c) 20 dB (d) 10 dB (e) 2 dB b. O c. (c) +10 dB Q27: In a communications system the components have the following properties: power gain = 0.3 input transducer / transmitter: transmission medium: receiver / output transducer: attenuation = 0.5 dB/km power gain = 125 Assuming that the transmission mediumis 175 km long, calculate the output power from the system for an input power of 20 dBm Q24: What is the signal to noise ratio of a communications system if the signal is 5 V and the noise is 5 mV (5 x 10 V)? (c) - 10 dB (d) + 30 dB (e) - 30 dB (a) - 60 dB a. O b. O c. d. e. QUESTION 27 QUESTION 25 Q25: What is the signal to noise ratio of a communications system if the signal is 5 W and the noise is 5 mW (5 x 10- W)? (a) + 60 dB (d) + 30 dB (e) - 60 dB b. O c. O d. e. (b) + 60 dB e. (b)- 30 dB QUESTION 26 Q26: In all communications systems all the devices and subsystems used add noise to the signals being transmitted through them. The output power of a receiver in the presence of a signal is 50 mW, while the output noise (i.e. output without a signal present) is 500 W. The signal to noise ratio is: (a) 100 dB (b) 25 dB (c) 20 dB (d) 10 dB (e) 2 dB b. O c. (c) +10 dB Q27: In a communications system the components have the following properties: power gain = 0.3 input transducer / transmitter: transmission medium: receiver / output transducer: attenuation = 0.5 dB/km power gain = 125 Assuming that the transmission mediumis 175 km long, calculate the output power from the system for an input power of 20 dBm