Electromagnetic Waves

JEE Main level, single correct, medium

47 of 165

Question 47 of 165

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.

Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar)

In the light of given statements, choose the correct answer from the options given below.

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Answer: (B) A is false but R is true

An optical telecommunication is communication at a distance using light to carry information. It can be performed visually or by using electronic devices.
The wavelength of the microwaves are greater than that of the common optical light waves.

Hence, the Assertion is not correct. But, because of the small wavelength, the electromagnetic waves are more energetic than the microwaves. Hence, the reason is true.

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