Invisible light is defined as which of the following?

Invisible light is defined as which of the following?

• A. The light that is invisible to the naked eye
• B. The light visible to the human eye
• C. Light that is always harmless to skin
• D. Light that only exists in the dark

Answer: (A)

Invisible light refers to wavelengths that the eye cannot perceive with the naked eye. This is why the correct choice describes it as light that is invisible to the naked eye. In practical terms, that includes ultraviolet and infrared radiation—ultraviolet can have enough energy to affect skin and eyes, while infrared is felt as heat. The other statements don’t fit because light that the eye can see isn’t invisible; not all invisible light is harmless to skin (UV can cause harm); and invisible light isn’t something that only exists in the dark—UV light, for example, can be present in daylight.

Invisible light refers to wavelengths that the eye cannot perceive with the naked eye. This is why the correct choice describes it as light that is invisible to the naked eye. In practical terms, that includes ultraviolet and infrared radiation—ultraviolet can have enough energy to affect skin and eyes, while infrared is felt as heat. The other statements don’t fit because light that the eye can see isn’t invisible; not all invisible light is harmless to skin (UV can cause harm); and invisible light isn’t something that only exists in the dark—UV light, for example, can be present in daylight.