Question

A teacher gives a convex lens and a concave mirror of focal length of 20 cm each to his student and asks him to find their focal lengths by obtaining the image of a distant object. The student uses a distant tree as the object and obtains its sharp image, one by one, on a screen. The distances d1 and d2 between the lens/mirror and the screen in the two cases and the nature of their respective sharp images are likely to be
(a) (20 cm, 40 cm) and (erect and erect)
(b) (20 cm, 40 cm) and (inverted and inverted)
(c) (20 cm, 20 cm) and (inverted and inverted)
(d) (20 cm, 40 cm) and (erect and inverted)
Give reason for your answer.

Answer 1

Answer:

The correct answer is option D

Answer 2

Answer:

Option (d) (20 cm, 40 cm) and (error and inverted) is the correct answer