Which of the following is a characteristic of light?

• A. Can only be created by artificial sources
• B. Can be bent by objects
• C. Can move without a source
• D. Always travels in a straight line

Answer: (B)

Light has several unique characteristics, and one of them is its ability to be bent, or refracted, when it passes through different media or encounters an obstacle. When light travels from one material to another, such as from air into water or glass, it changes speed due to the differing optical densities of the materials. This change in speed results in the bending of the light rays, which is the basis for phenomena like the bending of a straw in a glass of water or the formation of rainbows when light interacts with raindrops.

This bending of light is crucial in many practical applications, including the design of lenses for glasses, cameras, and microscopes, as well as in understanding the principles of optics more generally. Understanding how light behaves when it passes through various materials helps us to manipulate and utilize it in technologies that enhance vision and imaging.

The other options address concepts that do not accurately reflect the behavior of light. For instance, light can be produced by both natural sources (like the sun) and artificial sources (like light bulbs), it cannot move without a source as it needs an originating point to propagate, and while light typically travels in straight lines in a uniform medium, it can deviate in different media or when manipulated by lenses.