Question

An object is placed at the following distances from a concave mirror of focal length 15 cm, turn by turn : (a) 35 cm (b) 30 cm (c) 20 cm (d) 10 cm Which position of the object will produce : (i) a magnified real image ? (ii) a magnified virtual image ? (iii) a diminished real image ? (iv) an image of same size as the object ?

Answer 1

given:

Mirror type: concave mirror

Focal length:15cm

Radius of curvature: 2F= 30cm

(a) When the object is placed 35cm away from the concave mirror it will give a diminished real image since the object is placed beyond centre of curvature.

(b) When the object is positioned 30cm away from the mirror, it will give an image of the same size since the position of the object is at centre of curvature.

(c) When the object is positioned 20cm away from the mirror we will get an enlarged real image since the position of the object is between focus and centre of curvature.

(d) When the object is placed at 10cm away from the concave mirror it will give a virtual image which is magnified since the position of object is between focus and pole.

So we can conclude that

a) At 10cm we will get a magnified virtual image

b) At 20cm we will get an magnified real image

c) At 30cm we will get an image of same size

d) At 35cm we will get a diminished real image.