Which of the following devices allows light to focus, creating a real image?

Which of the following devices allows light to focus, creating a real image?

• A. Flat mirror
• B. Convex lens
• C. Opaque card
• D. Concave lens

Answer: (B)

The correct answer, which is the convex lens, effectively focuses light to create a real image. A convex lens is thicker in the middle than at the edges, which allows it to bend and converge light rays that travel through it. When parallel rays of light enter a convex lens, they are refracted and meet at a focal point on the opposite side of the lens. If an object is placed outside this focal point, the light rays from the object converge and create a real image that can be projected onto a screen. In contrast, a flat mirror merely reflects light without focusing or converging those rays, so it can generate a virtual image that appears behind the mirror but not a real one that can be projected. An opaque card blocks light entirely and does not allow any light to pass through or focus, eliminating the possibility of image formation. A concave lens, on the other hand, diverges light rays and only produces virtual images that cannot be projected onto a surface. Thus, the unique ability of the convex lens to converge light rays is what makes it the device that creates real images.

The correct answer, which is the convex lens, effectively focuses light to create a real image. A convex lens is thicker in the middle than at the edges, which allows it to bend and converge light rays that travel through it. When parallel rays of light enter a convex lens, they are refracted and meet at a focal point on the opposite side of the lens. If an object is placed outside this focal point, the light rays from the object converge and create a real image that can be projected onto a screen.

In contrast, a flat mirror merely reflects light without focusing or converging those rays, so it can generate a virtual image that appears behind the mirror but not a real one that can be projected. An opaque card blocks light entirely and does not allow any light to pass through or focus, eliminating the possibility of image formation. A concave lens, on the other hand, diverges light rays and only produces virtual images that cannot be projected onto a surface. Thus, the unique ability of the convex lens to converge light rays is what makes it the device that creates real images.