JEE Main202312 Apr 2023Morning ShiftPhysicsElectromagnetic WavesActual
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.
Options
- ABoth A and R are true but R is NOT the correct explanation of A
- BA is false but R is true
- CA is true but R is false
- DBoth A and R are true and R is the correct explanation of A
Correct answer
B. A is false but R is true
Step-by-step solution
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.