Lens Sign Convention: Practice Problems
Problem 1: An object is placed 15 cm in front of a converging lens with a focal length of 10 cm. Calculate the image distance and determine the nature (real or virtual), orientation (upright or inverted), and size of the image formed.
Problem 2: A 3.0 cm tall object is placed 20 cm in front of a converging lens with a focal length of 15 cm. Calculate the image distance and determine the nature (real or virtual), orientation (upright or inverted), and size of the image formed.
Problem 3: An object is placed 30 cm in front of a diverging lens with a focal length of -20 cm. Calculate the image distance and determine the nature (real or virtual), orientation (upright or inverted), and size of the image formed.
Lens Sign Convention
A lens in optics is a transparent device with curved surfaces that refract light. It can be converging or diverging based on its shape. The lens sign convention, or Cartesian sign convention, helps determine the nature, size, and position of images formed by lenses accurately. It clarifies the positive and negative signs for object and image distances, focal lengths, and magnifications, crucial for optical calculations and predictions.
Table of Content
- What is the Lens Sign Convention?
- Basics of Lens Sign Convention
- Cartesian Sign Convention
- Sign Conventions in Different Lenses
- Lens Maker’s formula
- Conclusion: Lens Sign Convention