## CBSE: NCERT Solutions for Class 12 Physics Chapter 15 Communication Systems MCQ’s with Answers

NCERT Books are textbooks which are issued & distributed by the National Council of Educational Research and Training (NCERT). NCERT books are important for the schooling system. NCERT Books are available in E-Books. If you are searching for MCQs (Multiple Choice Questions) with Answers of for NCERT Class 12 Physics  then you have came to right way. CBSE students can also solve NCERT Class 12 Physics Chapter 15 Communication Systems PDF Download their preparation level. MCQs are Prepared Based on Latest Exam Patterns. MCQs Questions with Answers for Class 12 Physics Chapter 15 Communication Systems are prepared to help students to understand concepts very well. Objective wise Questions 12th class Physics Chapter 15 Communication Systems Chapter wise PDF over here are available in the following links. Score maximum marks in the exam.

### NCERT Physics MCQs for Class 12 Question and Answers Chapter 15 Communication Systems PDF

Q1. Increase in frequency deviation results into:
(a) increase in noise of FM receiver
(b) decrease in noise of AM receiver
(c) increase in noise of Am receiver
(d) decrease in noise of FM receiver

Q2. Digital signals:
(a) deal with all sort of values
(b) can use decimal system
(c) can use binary system
(d) (b) and (c) both

Q3. AM is used for broadcasting because:
(a) it is more noise immune than other modulation system
(b) it requires less transmitting power compare with other systems
(c) its use avoids receiver complexity
(d) No other modulation system can provide the necessary bandwidth faithful transmission

Q4. Communication channel consists of:
(a) transmission line only
(b) optical fibre only
(c) free space only
(d) All of the above

(a) analog data communication
(b) digital data communication
(c) both (a) and (b) are equally good
(d) depends on the situation

Q6. In space communication, the sound waves can be sent from one place to another:
(a) through space
(b) through wires
(c) by superimposing it on undamped electro-magnetic waves
(d) by superimposing it on damped electro-magnetic waves

Answer:(c) by superimposing it on undamped electro-magnetic waves

Q7. The length of a half wave dipole at 30 mega-hertz is:
(a) 5 m
(b) 10 m
(c) 25 m
(d) 80 m

Q8 .The sound produced by a tuning fork is a sort of:
(a) analog signal
(b) digital signal
(c) both (a) and (b)
(d) neither (a) nor (b)

Q9. A loudspeaker converts:
(a) electrical signals into sound signals
(b) sound signals into electrical signals
(c) both (a) and (b)
(d) neither (a) nor (b)

Answer:(a) electrical signals into sound signals

Q10. A microphone converts:
(a) sound signals into electrical signals
(b) electrical signals into sound signals
(c) both (a) and (b)
(d) Neither (a) nor (b)

Answer:(a) sound signals into electrical signals

Q11. Name the man who was first to place his foot on the moon and in which year:
(a) Neil Armstrong, 1969
(b) James Van A lien, 1971
(c) Leonov, 1965
(d) None of these

(a) Ommi directional type
(b) Vertical type
(c) Horizontal type
(d) None

Q13. An antenna is:
(a) Inductive
(b) Capacitive
(c) Resistive
(d) A transformer

Q14. The space waves which are affected seriously by atmospheric conditions are:
(a) MF
(b) HUF
(c) VHF
(d) UHF

Q15. The wavelength of a wave of frequency 10 kHz is:
(a) 30 m
(b) 300 m
(c) 30 km
(d) 300 km

Q16. The audio frequencies range from:
(a) 20 Hz to 20.000 kHz
(b) 20 Hz to 20 kHz
(c) 20 kHz to 20.000 kHz
(d) None of these

Answer:(b) 20 Hz to 20 kHz

Q17. The term used “to collect the information about an object and a place without physical contact” is called :
(a) modulation
(b) communication
(c) amplification
(d) remote sensing

Q18. Who undertook the first space walk and in which year?
(a) Leonov 1965
(b) Neil Armstrong, 1969
(c) Rakesh Sharma. 1998
(d) None of these

Q19.The most commonly employed analog modulation technique in satellite communication is the
(a) amplitude modulation
(b) frequency modulation
(c) phase modulation
(d) All of the above.

Q20. Which one of the following can happen to the electromagnetic waves travelling in free space:
(a) Reflection
(b) Refraction
(c) absorption
(d) attenuation

Q21. High frequency waves are
(a) reflected by E layer.
(b) absorbed by F layer.
(c) affected by the solar cycle.
(d) capable of use for long-distance transmission.

Q22. Microwave link repeaters are typically 50 km apart,
(a) because of atmospheric attenuation.
(b) because of the earth’s curvature.
(c) to ensure that signal voltage may not harm the repeater.
(d) None of these.

Answer:(b) because of the earth’s curvature.

Q23. The numbers of geostationary satellites needed for uninterrupted global coverage is
(a) 3
(b) 4
(c) 2
(d) 1

Q24. The information bearing signal is called
(a) Base band signal
(b) digital signal
(c) Analog signal
(d) None of these