Question

a 10 cm tall object is placed in front of a concave mirror at the center of curvature of the mirror at 15 cm (r=2f) . what is the image distance from the center of the mirror 1

Answer 1

Answer :

Given -

• Concave Mirror
• Height of the Object = 10 cm
• The Object is placed at the centre of curvature of the mirror
• Focal length = -15 cm

To Find -

• Image Distance from the centre of the mirror ?

Solution -

Because, centre of curvature is double of the focal length.

So, The centre of curvature is at the Distance of 30 cm from the Pole.

Hence, Object Distance = - 30 cm

Now, Mirror Formula : 1/v + 1/u = 1/f.

⇒ 1/v + 1/-30 = 1/-15

⇒ 1/v - 1/30 = -1/15

⇒ 1/v = -1/15 + 1/30

⇒ 1/v = (-30+15)/450

⇒ 1/v = -15/450

⇒ 1/v = - 0.033

⇒ v = 1/-0.033

⇒ v = -30.30 cm

Hence, The Image Distance = (- 30.30 cm), which is approx to (- 30 cm).

Hence, the Image is formed at the centre of curvature.