JEE Physics 2023 Question with Solution

Given: Four electromagnetic waves are to be matched with their wavelength ranges.

Find: The correct correspondence between Microwave, Ultraviolet, X-ray, and Infra-red.

Step 1: Recall wavelength ranges of electromagnetic spectrum.

Different electromagnetic waves occupy specific wavelength regions as follows:

• Microwaves: Wavelength range is approximately $0.1\,m to 1\,mm$.
• Ultraviolet rays: Wavelength range is approximately $400\,nm to 1\,nm$.
• X-rays: Wavelength range is approximately $1\,nm to 10^{-3}\,nm$.
• Infra-red rays: Wavelength range is approximately $1\,mm to 700\,nm$.

Step 2: Match List I with List II.

$$\begin{aligned} \text{Microwave} &\rightarrow (IV) \\ \text{Ultraviolet} &\rightarrow (I) \\ \text{X-ray} &\rightarrow (II) \\ \text{Infra-red} &\rightarrow (III) \end{aligned}$$

Step 3: Select the correct option.

The matching corresponds to option (C).

Therefore, the correct option is C: $(A)-(IV),\ (B)-(I),\ (C)-(II),\ (D)-(III)$.

Quick Tip: Remember the order of electromagnetic spectrum from longer to shorter wavelengths: Radio $\rightarrow$ Microwave $\rightarrow$ Infra-red $\rightarrow$ Visible $\rightarrow$ Ultraviolet $\rightarrow$ X-rays $\rightarrow$ Gamma rays.