How Do Blacklights Make Things Glow?

Black lights emit ultraviolet (UV) light, which is mostly invisible to the human eye. They use special filters to allow only UVA and a small amount of visible light to pass through, creating a purplish glow. Certain materials, known as phosphors, absorb this UV light and re-emit it as visible light, causing them to glow. This property is used in various applications, such as forensics, diagnostics, and security, as well as in decorative settings.

What is the primary reason black lights do not illuminate a room like regular light bulbs?

• They are not as powerful as regular bulbs.

• They emit mostly ultraviolet light.

• They emit only visible light.

• They are designed to be energy-efficient.

What role do phosphors play in the functioning of black lights?

• They absorb UV light and emit visible light.

• They enhance the brightness of the black light.

• They block UV light from reaching the eyes.

• They absorb visible light and emit UV light.

Which of the following is NOT a common item that contains phosphors?

• Highlighter ink

• Neon paints

• Laundry detergents

• Regular water

How can black lights assist forensic investigators at a crime scene?

• By providing a source of heat.

• By illuminating the entire area.

• By capturing high-resolution images.

• By detecting natural phosphors in bodily fluids.

In what way are black lights used in the field of security?

• To verify the authenticity of IDs.

• To enhance video surveillance.

• To detect motion in dark areas.

• To provide emergency lighting.