12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Economics Government Budget and the Economy Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Interface Python with MySQL - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Database Concept - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Data Communication - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Data Structures - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Functions - New Previous year Question Papers Study Material - QB365 Set A
Published on: 27/05/2021
CBSE 12th Standard Physics Subject Communication Systems HOT Questions 1 Mark Questions With Solution 2021
Download CBSE Class 12th Standard CBSE Physics question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 12th Standard CBSE Physics
Questions + Answers key
Take MCQ Physics Test
1.
You are given three semiconductors A,B,C with respective band gaps of 3eV, 2eV and 1eV for use in a photodetector to detect \(\lambda \) = 1400nm . Select the suitable semiconductor. Give reasons
2.
A microwave telephone link operating at the cenral frequency of 10 GHz has been established .If 2 % of this is available for microwave communication channel, then how many telephones channels can be simultaneously granted if each telephone is allotted a band width of 8 KHz
3.
A TV tower has a height of 110m. How much population is covered by the TV broadcast if the average population density around the tower is 1000 km-2? Given that radius of Earth = 6.4 x 106m
4.
The TV transmission tower at a particular place has a height of 160m. What is its coverage range? By how much should the height be increased to double its coverage range? Given that radius of earth = 6400 km
5.
A schematic arrangement for transmitting a message signal (20 Hz to 20kHz) is given below:
Give two drawbacks from which this arrangement suffers. Describe briefly with the help of a block diagram the alternative arrangement for the transmission and reception of the message signal
1.
( )
Energy corresponding to \(\lambda \) = 1400nm = 1400 x 10-9 m is
E = \(\frac { hc }{ \lambda } =\frac { 1.42\times { 10 }^{ -19 } }{ 1.6\times { 10 }^{ -19 } } eV=1eV\)
For detection E must be equal to greater then Eg. Hence only suitable semiconductor is C.
2.
( )
Microwave communication channel width = \(\frac { 2 }{ 100 } \times 10GHz\)
= 0.2 Ghz
band width of channel = 8 KHz
= 2.5 x 104
3.
( )
Radius of the area covered by TV broadcast is
d = (2Rh)1/2
= 37500m = 37.5 km
= 4.4 x 106
4.
( )
d = (2 x 6400 x 103 x 160)1/2 = 45255m
Coverage range , d = (2Rh)1/2
h2 - 4h1 = 4 x 160 = 640 m
5.
( )
12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Computer Science Python Revision Tour I - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Planning Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Business Environment Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Principles of Management Important Questions And Answers Study Material - QB365 Set A
CBSE 12th Standard CBSE Subjects
CBSE Standards
