## Book: HC Verma - Concepts of Physics Part 1

### Chapter: 18. Geometrical Optics

#### Subject: Physics - Class 12th

##### Q. No. 66 of Exercises

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66
##### A converging lens of focal length 15 cm and a converging mirror of focal length 10 cm are placed 50 cm apart. If a pin of length 2.0 cm is placed 30 cm from the lens farther away from the mirror, where will the final image form and what will be the size of the final image?

focal length of the convex lens = 15cm

Concave mirror of focal length

Distance between lens and mirror= 50cm

Height of the object, = 2cm

Distance between object and the lens, u = 30cm

By using lens formula,

hence, real and inverted image (A’B’) will be formed at 30 cm from the lens and it will be of same size as the object.

Now, this image is at a distance 20 cm from the concave mirror. Since, 10 cm, this real image is at the centre of curvature of the mirror. So, the mirror will form an inverted image AB’ at the same place of same size. Again, due to refraction in the lens, the final image will be formed at AB and will be of same size as that of object.

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