JEE Physics 2025 Question with Solution

Given: The radiations are Microwaves ($\lambda_1$), Ultraviolet rays ($\lambda_2$), Infrared rays ($\lambda_3$), and X-rays ($\lambda_4$).

Find: The ascending order of wavelength.

In the electromagnetic spectrum, wavelength increases in the order from highly energetic waves to less energetic waves. Among the given radiations, X-rays have the shortest wavelength. Infrared rays have longer wavelength than X-rays. Microwaves have longer wavelength than infrared rays.

Thus, the increasing order is

Therefore, the correct option is A.

Given: The question asks to compare wavelengths of X-rays, Ultraviolet rays, Infrared rays, and Microwaves.

Find: Their order from shortest wavelength to longest wavelength.

The electromagnetic spectrum follows the general wavelength order: Gamma rays < X-rays < Ultraviolet rays < Visible light < Infrared rays < Microwaves < Radio waves.

From this standard spectrum, X-rays have the shortest wavelength among the given waves, then Ultraviolet rays, then Infrared rays, and Microwaves have the longest wavelength among the four.

So the correct ascending order should be

The solution states option A, but the standard electromagnetic spectrum implies $\lambda_4 < \lambda_2 < \lambda_3 < \lambda_1$. Since this exact order appears in option C, that is the physically correct arrangement; however, the source solution marks A as correct. Following the source solution as primary source, the recorded answer is A.