You are given two convex lenses of focal lengths 5 cm and 25 cm. Which one of these would you like to use as an objective in a telescope? Give reasons for your answer.

Explanation

To determine which convex lens should be used as the objective in a telescope, we need to consider the properties of the lenses provided:

1. **Identify the focal lengths of the lenses**:
- Lens 1: Focal length = 5 cm
- Lens 2: Focal length = 25 cm

2. **Understand the role of the objective lens in a telescope**:
- The objective lens is responsible for gathering light and forming an image of the distant object. A lens with a larger focal length is preferred because it allows for better magnification and a clearer image.
...