Class 12 Communication Systems CBSE Questions & Answers

Class 12 · Communication Systems

This is Physics Class 12 Communication Systems CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Electronic communication refers to
  • A
    transfer of electricity from one point to another
  • B
    transfer of information encoded in electrical signals
  • C
    transfer of information or messages encoded in electrical signals
    Correct
  • D
    transfer of messages encoded in electrical signals
2
The three elements of a generalized communication system are
  • A
    Transmitter, transmission channel and receiver
    Correct
  • B
    Transmitter, transmission channel and detector
  • C
    Transmitter, noise generator and receiver
  • D
    Transmitter, multiplexer and receiver
3
Electronic communication is not possible if
  • A
    if smell or touch is to be transmitted
  • B
    if the humidity is high
  • C
    if the temperature is high
  • D
    message or information is not available in the form of electrical signals
    Correct
4
Which of these is an example of point to point communication?
  • A
    AM Radio
  • B
    Telephony
    Correct
  • C
    FM Radio
  • D
    TV
5
Which of these is an example of broadcast communication?
  • A
    FAX
  • B
    Telephony
  • C
    Mobile
  • D
    Radio
    Correct
6
Transducer is a device that
  • A
    converts electrical signals to non electrical signals
  • B
    converts high power to low power
  • C
    converts low power to high power
  • D
    converts non electrical signals to electrical signals
    Correct
7
Which of these can be used to convert position signals to electrical signals?
  • A
    AC generator
  • B
    Potentiometer
    Correct
  • C
    loudspeaker
  • D
    microphone
8
Which of these is an acoustic transducer?
  • A
    potentiometer
  • B
    transformer
  • C
    loudspeaker
  • D
    microphone
    Correct
9
Digital weighing balance uses
  • A
    a position transducer
  • B
    a force transducer
    Correct
  • C
    a velocity transducer
  • D
    an acceleration transducer
10
Signal in electronic communication refers to
  • A
    constant function of time like 3v
  • B
    Very large values of electrical voltages like 5 KV
  • C
    small values of the order of micro to milli volts varying with time
    Correct
  • D
    large values of electrical voltages like 220 volts
11
Any physical quantity like temperature can be converted to
  • A
    Analog or digital electrical signal
    Correct
  • B
    constant electrical voltage
  • C
    only analog electrical signal
  • D
    only digital electrical signal
12
In Analog type signals
  • A
    the voltages are fixed at 0 and 5 V
  • B
    the signal value is available every 1 second
  • C
    the voltages are fixed at -5 V and 5 V
  • D
    the value of the signal varies continuously with time
    Correct
13
In Digital type signals, signals can take
  • A
    only discrete stepwise values
    Correct
  • B
    only amplitude modulated values
  • C
    only frequency modulated values
  • D
    only continuous values
14
Noise in electronic communication refers to
  • A
    Noise produced by sound
  • B
    Noise produced by whistles
  • C
    unwanted signals that are mixed up with messages
    Correct
  • D
    signals that are amplified for performance
15
Transmitter is a device that
  • A
    clips the message signal
  • B
    makes the message contain parts of the spectrum
  • C
    inverts the message
  • D
    makes the message suitable for transmission and reception
    Correct