The magnification of an image formed by a lens is – 1. If the distance of the image from the optical centre of the lens is 35 cm, where is the object placed ? What is the nature and focal length of the lens? If the object is displaced 20 cm towards the optical centre of the lens, where would the image be formed and what will be its nature? Draw a ray diagram to justify your answer.
CBSE FOREIGN - SET 2 2017
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- (m = - 1, i.e. Image is real, inverted and same size as the object.
- Nature of lens: Convex/ Converging.
- As 2f = 35 cm
- On displacing the object 20 cm towards the lens, the object distance becomes 15c m (35 cm – 20 cm) i.e. it lies between F and O of the lens. Image formed now is virtual/on the same side of lens as the object.
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