What type of telescope uses a refracting lens as its objective?

What type of telescope uses a refracting lens as its objective?

• A. Galilean
• B. Keplerian
• C. Newtonian
• D. Reflecting

Answer: (A)

The Galilean telescope is characterized by its use of a refracting lens as its objective. This type of telescope employs a convex lens to gather and focus light, which allows for the formation of an image that can be magnified. The design was developed by Galileo Galilei in the early 17th century, and it features an eyepiece that is a concave lens, producing an upright image that is useful for astronomical observations. This design contrasts with the Keplerian telescope, which also uses lenses but has a different configuration, leading to an inverted image. The Newtonian telescope employs a concave mirror instead of lenses as its primary light-gathering component, and the reflecting telescope, by definition, relies on mirrors to focus light rather than lenses. Thus, the defining feature of the Galilean telescope is its objective lens, which clearly distinguishes it from these other types of telescopes.

The Galilean telescope is characterized by its use of a refracting lens as its objective. This type of telescope employs a convex lens to gather and focus light, which allows for the formation of an image that can be magnified. The design was developed by Galileo Galilei in the early 17th century, and it features an eyepiece that is a concave lens, producing an upright image that is useful for astronomical observations.

This design contrasts with the Keplerian telescope, which also uses lenses but has a different configuration, leading to an inverted image. The Newtonian telescope employs a concave mirror instead of lenses as its primary light-gathering component, and the reflecting telescope, by definition, relies on mirrors to focus light rather than lenses. Thus, the defining feature of the Galilean telescope is its objective lens, which clearly distinguishes it from these other types of telescopes.