Digital Communications Questions and Answers – Modulation and Multiplexing

This set of Digital Communications Multiple Choice Questions & Answers (MCQs) focuses on “Modulation and Multiplexing”.

1. Properties used to determine stream’s fidelity
a) Sampling rate
b) Bit depth
c) Sampling rate & Bit depth
d) None of the mentioned
View Answer

Answer: c
Explanation: Two basic properties to determine stream’s fidelity are bit depth and sampling rate, number of times per second that samples are taken.

2. In bipolar codes, pulses can be
a) Positive
b) Negative
c) Absent
d) All of the mentioned
View Answer

Answer: d
Explanation: In bipolar codes, the pulses can be positive, negative or absent.

3. Delta modulation is ______ conversion.
a) Analog to digital
b) Digital to analog
c) Analog to digital and digital to analog
d) None of the mentioned
View Answer

Answer: c
Explanation: Delta modulation is the process of analog to digital and digital to analog conversion technique used for transmission of voice signals.
advertisement
advertisement

4. To achieve high signal to noise ratio, delta modulation must use
a) Under sampling
b) Over sampling
c) Aliasing
d) None of the mentioned
View Answer

Answer: b
Explanation: To achieve high signal to noise ratio, delta modulation must use over sampling techniques.

5. The demodulator in delta modulation technique is
a) Differentiator
b) Integrator
c) Quantizer
d) None of the mentioned
View Answer

Answer: b
Explanation: The demodulator used in delta modulation is a simple form of integrator.
Note: Join free Sanfoundry classes at Telegram or Youtube

6. Source of noise in delta modulation is
a) Granularity
b) Slope overload
c) Granularity & Slope overload
d) None of the mentioned
View Answer

Answer: c
Explanation: Sources of noise in delta modulation are granularity and slope overload.

7. When probability of receiving a symbol is 1 then how much information will be obtained?
a) Little information
b) Much information
c) No information
d) None of the mentioned
View Answer

Answer: c
Explanation: When the probability of receiving a symbol is 1 then the information obtained is zero.
advertisement

8. In channel encoding procedure
a) Redundancy bits are added
b) Errors are corrected
c) Redundancy bits are added & Errors are corrected
d) None of the mentioned
View Answer

Answer: c
Explanation: In channel encoding includes addition of redundancy to the signal such that any bit errors can be corrected.

9. Modulation process includes
a) Analog to digital conversion
b) Digital to analog conversion
c) All of the mentioned
d) None of the mentioned
View Answer

Answer: b
Explanation: Modulation procedure includes digital to analog conversion which produces a continuous time signal that can be sent through the channel.
advertisement

10. Switching exists in
a) Point to point communication
b) Broadcast communication
c) Point to point & Broadcast communication
d) None of the mentioned
View Answer

Answer: a
Explanation: Circuit connection in point to point communication is called as switching. Switching does not exist in broadcast communication or network.

11. Space division has dedicated
a) Paths
b) Time slots
c) Paths & Time slots
d) None of the mentioned
View Answer

Answer: a
Explanation: Space division has dedicated paths and time division has dedicated time slots.

12. In time division system, the actual switch is called as
a) Speech memory
b) Cross point
c) Connecting point
d) None of the mentioned
View Answer

Answer: a
Explanation: In time division, actual switch is called as speech memory and in space division actual switch is called as cross point.

13. In time division, connection is established using
a) Data exchange
b) Galvanic connection
c) Data exchange & Galvanic connection
d) None of the mentioned
View Answer

Answer: a
Explanation: In time division, connection is established using data exchange and in space division it is established using galvanic connections.

14. Analogue switches provides
a) Good bandwidth
b) Low distortion
c) Low cost
d) All of the mentioned
View Answer

Answer: d
Explanation: Some of the features of analogue switches are good bandwidth, low cost, low distortion, lower reliability.

15. Operations performed by switching system
a) Path establishment
b) Information exchange
c) Tariff computation
d) All of the mentioned
View Answer

Answer: d
Explanation: Operations performed by switching network are path establishment, information exchange, tariff computation, maintenance, billing etc.

Sanfoundry Global Education & Learning Series – Digital Communications.

To practice all areas of Digital Communications, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.