A narrow beam of light consisting of rays that are initially parallel to the…
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A narrow beam of light consisting of rays that are initially parallel to the principal axis is incident on a thin lens mounted on an optical bench. A movable screen is placed several tens of centimeters beyond the lens, but the screen can be removed at will.
Answer the following questions qualitatively—no numerical calculations are required.
(1) Describe the subsequent path of the light rays after they pass through a thin convex (converging) lens. In your answer, state the location of the point through which the rays (or their extensions) intersect the principal axis and indicate whether that point lies on the same side of the lens as the incident rays or on the opposite side.
(2) Repeat part (a) for a thin concave (diverging) lens.
(3) A distant star may be regarded as an object at infinity. For each lens type in parts (a) and (b), indicate whether a real image capable of being projected onto the movable screen can be formed. Justify your answer based on the ray behaviour you described.