NCERT Solutions For Class 12 Physics Chapter 15 Communication Systems PDF Download

NCERT Solutions For Class 12 Physics Chapter 15 Communication Systems

You can download the NCERT Solutions for Class 12 Physics Chapter 15 Communication Systems in PDF below. Prescribed textbook by CBSE for Chapter 15 Communication Systems is standard XII NCERT course book for Physics.

Question 15.1:
Which of the following frequencies will be suitable for beyond-the-horizon communication
using sky waves?
(a) 10 kHz
(b) 10 MHz
(c) 1 GHz
(d) 1000 GHz
Answer
(b) Answer:
10 MHz
For beyond-the-horizon communication, it is necessary for the signal waves to travel a large distance. 10 KHz signals cannot be radiated efficiently because of the antenna size.
The high energy signal waves (1GHz − 1000 GHz) penetrate the ionosphere. 10 MHz frequencies get reflected easily from the ionosphere. Hence, signal waves of such frequencies are suitable for beyond-the-horizon communication.

Question 15.2:
Frequencies in the UHF range normally propagate by means of:
(a) Ground waves.
(b) Sky waves.
(c) Surface waves.
(d) Space waves.
Answer
(d) Answer:
Space waves
Owing to its high frequency, an ultra high frequency (UHF) wave can neither travel along the trajectory of the ground nor can it get reflected by the ionosphere. The signals having UHF are propagated through line-of-sight communication, which is nothing but space wave propagation.

NCERT Solutions For Class 12 Physics Chapter 15 Communication Systems

Question 15.3:
Digital signals
(i) Do not provide a continuous set of values,
(ii) Represent values as discrete steps,
(iii) Can utilize binary system, and
(iv) Can utilize decimal as well as binary systems.
Which of the above statements are true?
(a) (i) and (ii) only
(b) (ii) and (iii) only
(c) (i), (ii) and (iii) but not (iv)
(d) All of (i), (ii), (iii) and (iv).
Answer
(c) Answer:
A digital signal uses the binary (0 and 1) system for transferring message signals. Such a system cannot utilise the decimal system (which corresponds to analogue signals).
Digital signals represent discontinuous values.

Question 15.4:
Is it necessary for a transmitting antenna to be at the same height as that of the receiving antenna for line-of-sight communication? A TV transmitting antenna is 81m tall. How much service area can it cover if the receiving antenna is at the ground level?
Answer
Line-of-sight communication means that there is no physical obstruction between the transmitter and the receiver. In such communications it is not necessary for the transmitting and receiving antennas to be at the same height.
Height of the given antenna, h = 81 m
Radius of earth, R = 6.4 × 10^6 m
For range, d = 2Rh, the service area of the antenna is given by the relation:
A = πd2
= π (2Rh)
= 3.14 × 2 × 6.4 × 10^6 × 81
= 3255.55 × 10^6 m^2
= 3255.55
NCERT Solutions for Class 12 Physics

 

NCERT Solutions For Physics XII NCERT Help Book

Physics NCERT Guide For Class 12 Chapter 15 Communication Systems contain solved questions answers in PDF for free download based on latest guide for NCERT Books 12th Standard Physics in new pattern as per CBSE Syllabus for Class 12 Physics 2018-19.

Syllabus, Solutions, Answers, CBSE Help Books for Chapter 15 Communication Systems Class 12 Physics

Central Board of Secondary Education governs the teaching pattern for XII Physics. For all the schools affiliated to CBSE Prescribed book for Chapter 15 Communication Systems is NCERT for Class 12 Physics. NCERT solutions for Class 12 Physics make learning easy. Teaching the right way of problem solving and make topics clear to the students of 12th is necessary. These NCERT Solutions For Class 12 Physics Chapter 15 Communication Systems will help them in preparation for 12th Standard Physics Exams.

Aiming at securing high marks with improved basic fundamental knowledge in Physics should be the goal. Above given solutions for NCERT books XII Physics contain questions and answers covering all topics. Important concepts of Chapter 15 Communication Systems in PDF is available for free download. As per new CBSE Syllabus for XII Physics Chapter 15 Communication Systems is included in curriculum.

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