Home
Class 12
PHYSICS
What is the carrier wave? Why high frequ...

What is the carrier wave? Why high frequency carrier waves are employed for transmission?

A

stationary wave

B

carrier wave

C

modulated wave

D

audio wave

Text Solution

Verified by Experts

The correct Answer is:
B
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • COMMUNICATION SYSTEMS

    NIKITA PUBLICATION|Exercise Multiple Choice Questions (Production and detection of amplitude modulated wave)|31 Videos

  • COMMUNICATION SYSTEMS

    NIKITA PUBLICATION|Exercise Multiple Choice Questions (Space communication )|58 Videos

  • COMMUNICATION SYSTEMS

    NIKITA PUBLICATION|Exercise Multiple Choice Questions (Bandwidth of signals)|7 Videos

  • CIRCULAR MOTION

    NIKITA PUBLICATION|Exercise Multiple Choice Question|421 Videos

  • CURRENT ELECTRICITY

    NIKITA PUBLICATION|Exercise Multiple Choice Questions|314 Videos

Similar Questions

Explore conceptually related problems

High frequency waves are

The modulating frequency is 5kHz and the carrier frequency is 100kHz .What is the band width of AM transmission?

Knowledge Check

  • Both amplitude modulation (AM) and frequency modulation (FM) are used for radio broadcasting. The amplitude of the high frequency carrier wave is varied or modulated in accordance with the variations in the amplitude of the audio signals that are to be transmitted, in te process of amplitude modulation in frequency modulation te amplitude of the carrier remains constant but its frequency is varied inn accordance withh the audio signal. Reception with AM signals is in general is affected by interference of various kinds ad elaborated equipment is required for FM broadcast. A radio frequency carrier wave can be modulated using a-

    A
    diode
    B
    triode
    C
    diode or a triode
    D
    none of the above

  • The process by which some characteristics i.e. amplitude, phase or frequency of hight frequency carrier wave is varied with information signal is

    A
    demodulation
    B
    modulation
    C
    amplification
    D
    oscillation

  • The device used for addition of high frequency carrier wave and information signal is

    A
    amplifier
    B
    rectifier
    C
    modulator
    D
    demodulator

    • Similar Questions

    Explore conceptually related problems

    What is the range of frequencies used for TV transmission? What is common between these waves and light waves?

    The efficient transmission of signals is achieved by superimposing electrical audio signals on a high frequency carrier wave (the process is known as modulation). When the amplitude of high frequency carrier wave is changed in accordance with the intensity of modulating signal, it is called amplitude modulation. The extent to which the amplitude of carrier wave is changed by the signal is described by modulation factor. It is given as m="Amplitude change of carrier wave"/"Amplitude of unmodulated carrier wave" Let a carrier wave is represented by V_c=V_c cos omega_ct Let the modulation factor be m, the maximum change in amplitude of carrier wave is mV_c So, modulating signal can be represented as v_m=mV_c cosomega_mt So, the amplitude of modulated wave is =V_c+mV_c cosomega_m t Using this value, the instantaneous voltage of modulated wave is E=V_c cos omega_c t+ (mV_c)/2 cos (omega_c+omega_m)t + (mV_c)/2 cos (omega_c-omega_m ) t The above wave contains three frequencies namely, f_c, f_c+f_m and f_c-f_m . The frequencies f_c+f_m and f_c-f_m are called side band frequencies , USB and LSB respectively. The fraction of total power carried by side band frequencies is

    The efficient transmission of signals is achieved by superimposing electrical audio signals on a high frequency carrier wave (the process is known as modulation). When the amplitude of high frequency carrier wave is changed in accordance with the intensity of modulating signal, it is called amplitude modulation. The extent to which the amplitude of carrier wave is changed by the signal is described by modulation factor. It is given as m="Amplitude change of carrier wave"/"Amplitude of unmodulated carrier wave" Let a carrier wave is represented by V_c=V_c cos omega_ct Let the modulation factor be m, the maximum change in amplitude of carrier wave is mV_c So, modulating signal can be represented as v_m=mV_c cosomega_mt So, the amplitude of modulated wave is =V_c+mV_c cosomega_m t Using this value, the instantaneous voltage of modulated wave is E=V_c cos omega_c t+ (mV_c)/2 cos (omega_c+omega_m)t + (mV_c)/2 cos (omega_c-omega_m ) t The above wave contains three frequencies namely, f_c, f_c+f_m and f_c-f_m . The frequencies f_c+f_m and f_c-f_m are called side band frequencies , USB and LSB respectively. If modulation factor is 100% , the amplitude change of carrier wave is

    In amplitude modulation, carrier wave frequencies are:

    The process in which amplitude of the high frequency carrier wave changes accordance with the instantaneous value of modulated signal is

    Home
    Profile