Question

An object is kept at the following distances from a concave mirror of focal length 15 cm. (a) 10cm (b) 20 cm (c) 30 cm (d) 35 cm. In which of these cases :- 1. a real image of the same size will be formed. 2. a virtual enlarged image 3. real diminished image 4. a real enlarged image

Answer 1

1) a real image of the same size -30cm
2)a virtual enlarged image-10cm
3)a real diminished image -35 cm
4)a real enlarged image -20cm

Answer 2

Given focal lengh = 15
Therefore, centre of curvature = 30 cm
1. Real and inverted image is formed by an object at c so the object distance is 30 cm
2.a virtual enlarged image will be formed by the object placed in between p and f so the object distance is 10cm
3. Real diminished image is formed by the object beyond c so the object distance is 35 cm.
4. real enlarged image is formed by an object placed between c and F so the object distance is 20cm