gen-define-a-converging-versus-diverging-lens-and-give-one-short-ff27

Define a converging versus diverging lens and give one short worked example.

# Converging vs Diverging Lens ## **Converging Lens (Convex)** - Thicker in the middle than at the edges - Bends parallel light rays **inward** to meet at a focal point - Has a **positive** focal length - Can form real or virtual images ## **Diverging Lens (Concave)** - Thinner in the middle than at the edges - Bends parallel light rays **outward** as if coming from a focal point - Has a **negative** focal length - Forms only virtual, upright, reduced images --- ## **Worked Example** **Problem:** An object is placed 30 cm from a converging lens with focal length f = 10 cm. Find the image distance and magnification. **Solution:** Using the thin lens equation: $$\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}$$ $$\frac{1}{10} = \frac{1}{30} + \frac{1}{d_i}$$ $$\frac{1}{d_i} = \frac{1}{10} - \frac{1}{30} = \frac{3-1}{30} = \frac{2}{30}$$ $$d_i = 15 \text{ cm}$$ Magnification: $$m = -\frac{d_i}{d_o} = -\frac{15}{30} = -0.5$$ **Answer:** The image is 15 cm on the opposite side of the lens, real, inverted, and half the object's size.