Question

Find out the electromagnetic radiation which has the longest wavelength?
(A) Gamma rays
(B) Ultraviolet
(C) Blue light
(D) X-rays
(E) Orange light

Answer 1

Hint For such cases when you are asked to find which has maximum length, which ray has maximum penetration power or any other such property then you should know the theory part. Like properties, symbols and representation. Such questions are time saver and will get will marks easily.

Complete step by step answer:
Electromagnetic Waves have different wavelengths.
Television waves, radio waves, and microwaves all these are types of electromagnetic waves. They only differ from each other in wavelength. Wavelength is defined as the distance between one wave crest to the next.
EM(electromagnetic) radiation spans a vast range of wavelengths and frequencies. This range is known as the electromagnetic spectrum. The electromagnetic spectrum is generally divided into seven different regions, in order of decreasing wavelength and increasing frequency and energy. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays. As lower-energy radiation, such as radio waves, is expressed as frequency; microwaves, infrared, visible and UV light are usually expressed as wavelength; and higher-energy radiation, such as X-rays and gamma rays, is expressed in terms of energy per photon.
The order of electromagnetic spectrum from longest wavelength to shortest is: radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.

Hence option B is correct.

Note Electromagnetic radiation can be expressed in terms of frequency, energy, wavelength. Frequency is measured in cycles per second, or Hertz(Hz). Wavelength is measured in meters. Energy is measured in electron volts. Each of the three quantities for describing electromagnetic radiation are related to each other in an accurate mathematical way.