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The various positions of an object from a convex lens and the relative sizes of the images formed in each position are tabulated below. Look at the data carefully and answer the questions that follow the table :
S.No. Position of object from lens (cm) Relative size of image (cm)
1. 45 Smaller than object
2. 30 Same size as object
3. 20 Magnified
4. 10 Magnified
(a) What is the focal length of the lens ?
S.No. Position of object from lens (cm) Relative size of image (cm)
1. 45 Smaller than object
2. 30 Same size as object
3. 20 Magnified
4. 10 Magnified
(a) What is the focal length of the lens ?
Show SolutionHide Solution↓
(a) 15 cm (1 Mark)
(b) :
Observation 3: Real and inverted image is formed. (1 Mark)
Observation 4: Virtual and erect image is formed. (1 Mark) (3 Marks)
(b) :
Observation 3: Real and inverted image is formed. (1 Mark)
Observation 4: Virtual and erect image is formed. (1 Mark) (3 Marks)