How are the types of energy in the electromagnetic spectrum defined? (Points : 3)
by their atomic structure

by their color

by their amplitude

by their wavelength

2 Answer

  • The correct answer to the question is : C) By their wavelength


    Before going to answer this question, first we have to understand the electromagnetic spectrum.

    An electromagnetic wave is the transverse wave which contains time varying electric field and magnetic field which are perpendicular to each other as well as perpendicular to the direction of propagation.

    There are various electromagnetic waves which are named as gamma ray, X-ray, U.V ray, visible light, infrared wave, micro wave and radio waves respectively. Out of these waves, only visible light can be visualized by human eye.

    Every electromagnetic wave is characterized by its wavelength. Different waves have different range of wavelength.

    The electromagnetic spectrum is the the arrangement of electromagnetic waves either in ascending order of wavelength or in descending order.

    The gamma ray has the minimum wavelength in the spectrum, and radio wave has the maximum wavelength.

    The energy carried by electromagnetic waves having wavelength [tex]\lambda[/tex] is calculated as-

                      Energy = [tex]\frac{hc}{\lambda}[/tex]

    Here, c is the velocity of light and h is the Planck' s constant.

    Hence, the correct answer to the question is wavelength which will signify the energy of different types of electromagnetic waves.

  • The energy associated with the electromagnetic spectrum is given by the wavelength of the spectrum.

    Further Explanation:

    The electromagnetic waves are the waves which travel through the space and do not require any medium for their propagation. The Electromagnetic waves are the waves which are transverse in nature.

    There are several waves of various wavelength and frequency present in the Electromagnetic spectrum. The different waves present in the electromagnetic spectrum are:

    • Gamma rays.
    • X-rays.
    • Ultraviolet rays.
    • Visible rays.
    • Infrared rays.
    • Micro waves.
    • Radio waves.

    The wavelength and the frequency of the electromagnetic waves are the key properties of the wave which describe several other parameters of the waves like intensity, power, energy of the wave etc.

    The energy associated with the electromagnetic radiation is given by:


    Here, [tex]E[/tex]  is the energy of the radiation, [tex]h[/tex]  is the plank’s constant, [tex]c[/tex]  is the speed of the light and [tex]\lambda[/tex]  is the wavelength of the radiation.

    Therefore, the above expression shows that the energy of the electromagnetic spectrum depends on the wavelength of the spectrum.

    Thus, Option (d) is correct. The energy of the electromagnetic spectrum is defined by their wavelength.

    Learn More:

    1. What is the threshold frequency ν0 of cesium

    2. Calculate the wavelength of an electron (m = 9.11 × 10-28 g) moving at 3.66 × 106 m/s

    3. What is the kinetic energy of the emitted electrons when cesium is exposed to UV rays

    Answer Details:

    Grade: High School

    Subject: Physics

    Physics: Electromagnetic spectrum


    Electromagnetic spectrum, energy, frequency, wavelength, radiation, speed of light, defined by their wavelength, E=hc/lamda, waves, transverse nature.