Question

Electromagnetic waves with wavelength

1. λ₁ is used in satellite communication.
2. λ₂ is used to kill germs in water purifies.
3. λ₃ is used to detect leakage of oil in underground pipelines.
4. λ₄ is used to improve visibility in runways during fog and mist conditions.

1. Identify and name the part of electromagnetic spectrum to which these radiations belong.
2. Arrange these wavelengths in ascending order of their magnitude.
3. Write one more application of each.

Answer 1

a. (i) In satellite communications, microwave is widely used. Hence λ₁, is the wavelength of microwave.

(ii) In water purifier, ultraviolet rays are used to kill germs. So, λ₂ is the wavelength of UV rays.

(iii) X-rays are used to detect leakage of oil in underground pipelines. So, λ₃ is the wavelength of X-rays.

(iv) Infrared rays are used to improve visibility on runways during fog and mist conditions. So, it is the wavelength of infrared waves.

b. Wavelength of X-rays < wavelength of UV < wavelength of infrared < wavelength of microwave.

⇒ λ₃ < λ₂ < λ₄ < λ₁

c. 

Radiation	Uses
γ-rays	Gives information on nuclear structure, medical treatment etc.
X-rays	Medical diagnosis and treatment study of crystal structure, industrial radiograph.
UV-rays	Preserve food, sterilizing the surgical instruments, detecting invisible writings, fingerprints etc.
Visible light	To see objects
Infrared rays	To treat, muscular strain from taking photography during the fog, haze etc.
Microwave and radio wave	In radar and telecommunication.