Game Preview

Electromagnetic wave. AM & FM

  •  English    15     Public
    to learn EMW
  •   Study   Slideshow
  • Name the part of the electromagnetic spectrum of wavelength 10-2 m and mention its one application.
    in microwave ovens1)in radar communication 2)in microwave ovens
  •  5
  • Write the following radiations in ascending order in respect of their frequencies ; X-rays, Microwaves, UV rays and radiowaves.
    Radiowaves, microwaves, UV-rays and X-rays.
  •  5
  • Name the EM waves used for studying crystal structure of solids. What is its frequency range?
    X-rays frequency range : 1017 Hz to 1020 Hz
  •  5
  • Which part of electromagnetic spectrum is absorbed from sunlight by ozone layer?
    Ultraviolet rays are absorbed from sunlight by ozone layers.
  •  5
  • Which part of electromagnetic spectrum is used in radar systems? (
    Microwave region of electromagnetic spectrum is used in radar systems.
  •  5
  • A plane electromagnetic wave travels in vacuum along z-direction. What can you say about the direction of electric and magnetic field vectors?
    The direction of electric field vector is along X-axis. Magnetic field vector is along Y-axis.
  •  10
  • How are radio waves produced?
    produced by the accelerated motion of charges in conducting wires
  •  10
  • What are the directions of electric and magnetic field vectors relative to each other and relative to the direction of propagation of electromagnetic waves?
    The oscillations of E and B fields are perpendicular to each other as well as to the direction of propagation of the wave.
  •  15
  • The speed of an electromagnetic wave in a material medium is given by v=1\√με. μ the permeability of the medium and ε its permittivity. How does its frequency change?
    Frequency remains unchanged.
  •  10
  • How are infrared waves produced?Write their one important use.
    produced by hot bodies,molecules, used to take photographs in darkness and to study secret writin, also used in physical therapy
  •  15
  • What is amplitude modulation?
    Amplitude modulation is a process by which the wave signal is transmitted by modulating the amplitude of the signal, frequency remains constant.
  •  15
  • What is the FM?
    the modulation of a radio or other wave by variation of its frequency, especially to carry an audio signal, amplitude of carrier wave remain constant
  •  15
  • what is bandwidth ?
    ... is the range of frequencies occupied by a modulated radio-frequency signal, usually given in hertz
  •  20
  • State the name components of the frequency spectrum, determine the frequency of audio signal.
    Carrier wave frequency=50 kHz,sidebands, audio signal f=5kHz
  •  20
  • Determine the wavelength of the carrier wave for this transmission
    500 m
  •  15