Which device uses two convex lenses to form enlarged images of distant objects?

Which device uses two convex lenses to form enlarged images of distant objects?

• A. Reflecting telescope
• B. Refracting telescope
• C. Catadioptric telescope
• D. Radio telescope

Answer: (B)

Two convex lenses work together to magnify distant objects by forming an image with the objective lens and then enlarging that image with the eyepiece. The objective gathers light from a faraway object and brings it to a real, inverted image at its focal plane. The eyepiece acts as a magnifying glass, making that image appear larger to the eye. The overall magnification is roughly the ratio of the objective’s focal length to the eyepiece’s focal length, so a longer objective focal length or a shorter eyepiece focal length increases zoom. Reflecting telescopes rely on mirrors instead of lenses. Catadioptric designs combine mirrors and lenses, not just two convex lenses. Radio telescopes collect radio waves with a dish and detectors rather than forming optical images with lenses.

Two convex lenses work together to magnify distant objects by forming an image with the objective lens and then enlarging that image with the eyepiece. The objective gathers light from a faraway object and brings it to a real, inverted image at its focal plane. The eyepiece acts as a magnifying glass, making that image appear larger to the eye. The overall magnification is roughly the ratio of the objective’s focal length to the eyepiece’s focal length, so a longer objective focal length or a shorter eyepiece focal length increases zoom.

Reflecting telescopes rely on mirrors instead of lenses. Catadioptric designs combine mirrors and lenses, not just two convex lenses. Radio telescopes collect radio waves with a dish and detectors rather than forming optical images with lenses.