Practice Quiz in Digital and Data Communication Networks Part 1

Question 1. The EIA standard specified in the EIA-232 standard is ______ volts.

Question 2. In trellis coding. The number of the data bits is _____ the number of transmitted bits.

Question 3. For a quaternary phase shift keying (QPSK) modulation, data with a carrier frequency of 70 MHz, and input bit rate of 10 Mbps, determine the minimum Nyquist bandwidth.

Question 4. A coherent binary phase shift keyed (BPSK) transmitter operates at a bit rate of Mbps with a carrier to noise ratio C/N of 8.8 dB. Find Eb/No.

Question 5. For sample rate of 30 kHz in a PCM system, determine the maximum analog input frequency.

Question 6. In QAM, both phase and ________ of a carrier frequency are varied.

Question 7. The signal between two modems is always

Question 8. A telephone line has a bandwidth of 3.2 kHz and a signal-to-noise ratio of 34 dB. A signal is transmitted down this line using a four-level code. What is the maximum theoretical data rate?

Question 9. Data are sent over pin ________ of the EIA-RS-232 interface.

Question 10. An asynchronous communications system uses ASCII at 9600 bps with eight bits, one start bit, one stop bit and no parity bit. Express the data rate in words per minute. (Assume a word has five characters and one space).