A tabletop slide projector uses a thin converging lens of focal length 10 cm to…
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A tabletop slide projector uses a thin converging lens of focal length 10 cm to display a photographic slide that is 5.0 cm tall onto a vertical screen situated 3.00 m from the lens. The projected image on the screen must completely fill a rectangular area that is 2.50 m tall.
(a) Determine the numerical lateral magnification required for the projected image to match the screen height.
(b) Calculate the numerical distance between the slide and the lens that will achieve the required magnification.
(c) Find the distance between the lens and the screen predicted by your calculation in part (b) and compare it with the given 3.00 m separation. State whether the design goal is exactly met, attainable only by moving the screen, or unattainable, and justify your conclusion.
(d) If the projector lens were replaced with a lens of a different focal length while leaving all other distances unchanged, should the new focal length be greater than, less than, or equal to 10 cm to achieve the same image size on the same fixed screen? Explain your reasoning qualitatively.