Question

which numbered area on the electromagnetic spectrum shown below contains visible light? gamma rays ① ultraviolet rays infrared rays ③ fm ④ shortwave 10⁻¹⁴ 10⁻¹² 10⁻¹⁰ 10⁻⁸ 10⁻⁶ 10⁻⁴ 10⁻² 1 10² wavelength (meters) 1 2 3 4

Explanation:

To determine the area containing visible light, we recall the electromagnetic spectrum: visible light has wavelengths between approximately \( 4 \times 10^{-7} \, \text{m} \) and \( 7 \times 10^{-7} \, \text{m} \) (or \( 400 \, \text{nm} \) to \( 700 \, \text{nm} \)).

Looking at the given spectrum:

• Gamma rays, X - rays (area 1) have very short wavelengths (\( < 10^{-8} \, \text{m} \)).
• Ultraviolet (UV) has wavelengths \( \approx 10^{-8} - 4\times10^{-7} \, \text{m} \), and infrared (IR) has \( \approx 7\times10^{-7}-10^{-3} \, \text{m} \). The region between UV (\( 10^{-8} \, \text{m} \)) and IR (\( 10^{-6} - 10^{-4} \, \text{m} \)) is where visible light lies. In the diagram, area 2 is between UV (\( 10^{-8} \, \text{m} \)) and IR (\( 10^{-6} \, \text{m} \) range), which matches the wavelength range of visible light. Areas 3 and 4 are for longer - wavelength radio waves (FM, shortwave) with wavelengths \( > 10^{-2} \, \text{m} \), which are much longer than visible light wavelengths.

Answer:

The numbered area containing visible light is 2.