2022 · Q23
A convex lens has a focal length of 15 cm. At what distance should an object be placed in front of the lens to get a real image of the same size of the object?
General KnowledgePhysics
- A15 cm
- B10 cm
- C30 cm
- D40 cm
Explanation
A real image of the same size has magnification −1, which occurs when the object is at the centre of curvature, 2F, from the lens. With f = 15 cm, 2F = 30 cm.