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Question
Electromagnetic waves with wavelength
- λ1 is used in satellite communication.
- λ2 is used to kill germs in water purifies.
- λ3 is used to detect leakage of oil in underground pipelines.
- λ4 is used to improve visibility in runways during fog and mist conditions.
- Identify and name the part of electromagnetic spectrum to which these radiations belong.
- Arrange these wavelengths in ascending order of their magnitude.
- Write one more application of each.
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Solution
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. |
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