Question

7 what is true about the electromagnetic spectrum? a it shows how frequency increases as wavelength increases b it excludes radio and ultraviolet waves c it includes all forms of energy d it includes all types of light

Explanation:

• Option A: The relationship between frequency ($f$) and wavelength ($\lambda$) is given by $c = f\lambda$ (where $c$ is the speed of light, constant in a medium). So frequency and wavelength are inversely proportional. As wavelength increases, frequency decreases. Thus, A is false.
• Option B: The electromagnetic spectrum includes radio waves (longest wavelength, lowest frequency) and ultraviolet waves (shorter wavelength than visible light, higher frequency than visible light). So B is false.
• Option C: The electromagnetic spectrum includes only electromagnetic energy (like light, radio waves, X - rays, etc.). There are other forms of energy like mechanical energy (kinetic, potential), nuclear energy, etc., that are not part of the electromagnetic spectrum. So C is false.
• Option D: The electromagnetic spectrum includes all types of light, both visible (like the colors we see) and invisible (like radio waves, microwaves, infrared, ultraviolet, X - rays, gamma rays). So D is true.

Answer:

D. It includes all types of light