CBSE
Multiple Choice QuestionsAssertion: Television signals are received through sky-wave propagation.
Reason: The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: Microwave communication is peferred over optical communication.
Reason: Microwaves provide large number of channels and bandwidth compared to optical signals.
if both assertion and reason are true but reason is the correct explanation of assertion
if both assertion and reason are true and the reason is not the correct explanation of assertion
if assertion is true and reason is false
if both assertion and reason are false statements
Assertion: In high latitudes one sees colourful curtains of light hanging down from high altitudes.
Reason: The high energy charged particles from the are deflected to polar regions by the magnetic field of the earth.
if both assertion and reason are true and the reason is the correct explanation of the assertion
if both assertion and reason are true and the reason is not the correct explanation of the assertion
if assertion is true but reason is false
if both assertion and reason are false statements
High-frequency waves are
affected by the solar cycle
reflected by layer
absorbed by the
capable of use for long-distance communication on the moon
The principle of LASER action involves
amplification of particular frequency emitted by the system
population inversion
stimulated emission
All of the above
Through which mode of propagation, the radio waves can be sent from one place to another?
Ground wave propagation
Sky wave propagation
Space wave propagation
All of the above
The binary number 10111 is equivalent to the decimal number
19
31
23
22
To write the decimal number 37 in binary, how many binary digits are required ?
5
6
7
4
The decimal equivalent of the binary number (11010.101)2 is
9.625
25.265
26.625
26.265
The decimal number equivalent to a binary number 1011001 is
13
17
89
178
