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231. A digitized voice channel is made by digitizing a 4-kHz bandwidth analog voice signal. We need to sample the signal at twice the highest frequency (two samples per hertz). We assume that each sample requires 8 bits. What is the required bit rate?
a. 64 kbps
b. 32 kbps
c. 128 kbps
d. 16 kbps
Discuss
Answer: (a).64 kbps

232. What is the bit rate for high-definition TV (HDTV)?
a. 1.4 Gbps
b. 2 Gbps
c. 1.5 Gbps
d. 1.8 Gbps
Discuss
Answer: (c).1.5 Gbps

233. A device is sending out data at the rate of 1000 bps. How long does it take to send a file of 100,000 characters?
a. 200s
b. 400s
c. 600s
d. 800s
Discuss
Answer: (d).800s

234. A file contains 2 million bytes. How long does it take to download this file using a 56-Kbps channel?
a. 1-2 mins
b. 5-6 mins
c. 2-4 mins
d. 7-8 mins
Discuss
Answer: (b).5-6 mins

235. We need to send 265 kbps over a noiseless channel with a bandwidth of 20 kHz. How many signal levels do we need?
a. 1024
b. 512
c. 256
d. 128
Discuss
Answer: (d).128

236. Calculate the theoretical highest bit rate of a regular telephone line. The signal-to-noise ratio is usually 3162.
a. 34.860 kbps
b. 17.40 kbps
c. 11.62 kbps
d. none of the Mentioned
Discuss
Answer: (a).34.860 kbps

237. Calculate the theoretical channel capacity. If SNR(dB) = 36 and the channel bandwidth is 2 MHz.
a. 12 Mbps
b. 24 Mbps
c. 16 Mbps
d. 32 Mbps
Discuss
Answer: (b).24 Mbps

238. A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate bit rate?
a. 4 Mbps
b. 6 Mbps
c. 8 Mbps
d. 12 Mbps
Discuss
Answer: (b).6 Mbps

239. A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate signel level?
a. 2
b. 8
c. 4
d. 16
Discuss
Answer: (c).4