How does the focal length of a magnifying glass change when immersed in water?

Explanation:

When light passes from air to water, it bends or refracts. This bending is caused by the change in speed of light in different media. The refractive index of water is greater than that of air. When the magnifying glass is immersed in water, the light from the object being examined passes from water to glass to air. As the light passes through the curved surface of the magnifying glass, it bends and converges at a point behind the lens, creating a magnified image.

The focal length of a lens is the distance between the center of the lens and the point where parallel rays of light converge after passing through the lens. When the magnifying glass is immersed in water, the refractive index of the lens changes, causing the light to bend more as it passes through the lens. This means that the distance between the center of the lens and the point where the light converges, i.e., the focal length, decreases.

Therefore, the focal length of the magnifying glass will decrease when it is immersed in water.