Question

The correct increasing order of wavelength for UV, Visible light, and Microwaves is:

• A. UV $\lt $ Visible $\lt $ Microwaves
• B. Microwaves $\lt $ Visible $\lt $ UV
• C. Visible $\lt $ UV $\lt $ Microwaves
• D. UV $\lt $ Microwaves $\lt $ Visible

Hint:

Remember that energy and frequency are inversely proportional to wavelength ($E = h\nu = hc/\lambda$).
Since UV has the highest energy among the three, it must have the shortest wavelength, while Microwaves have the lowest energy and the longest wavelength.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the correct increasing order of wavelength for three components of the electromagnetic spectrum: Ultraviolet (UV) radiation, Visible light, and Microwaves.

Step 2: Key Formula or Approach:
We recall the organization of the electromagnetic spectrum in terms of wavelength ($\lambda$).
The general order from shortest to longest wavelength is:
Gamma Rays $\rightarrow$ X-Rays $\rightarrow$ Ultraviolet $\rightarrow$ Visible $\rightarrow$ Infrared $\rightarrow$ Microwaves $\rightarrow$ Radio Waves.

Step 3: Detailed Explanation:

• Let us examine the specific wavelength ranges for the three types of radiation mentioned:
1.

Ultraviolet (UV) Radiation: Wavelength ranges approximately from $10\text{ nm}$ to $400\text{ nm}$ ($10^{-8}\text{ m}$ to $4 \times 10^{-7}\text{ m}$).
2.

Visible Light: Wavelength ranges approximately from $400\text{ nm}$ to $700\text{ nm}$ ($4 \times 10^{-7}\text{ m}$ to $7 \times 10^{-7}\text{ m}$).
3.

Microwaves: Wavelength ranges approximately from $1\text{ mm}$ to $1\text{ m}$ ($10^{-3}\text{ m}$ to $1\text{ m}$).

• Comparing these values, we have:
\[ 10\text{ nm} - 400\text{ nm} \ (\text{UV}) \lt 400\text{ nm} - 700\text{ nm} \ (\text{Visible}) \lt 1\text{ mm} - 1\text{ m} \ (\text{Microwaves}) \]

• Therefore, the correct increasing order of wavelength is:
\[ \text{UV} \lt \text{Visible} \lt \text{Microwaves} \]


Step 4: Final Answer:
The correct increasing order of wavelength is represented by option (A).