An object is placed 15cm in front of a plane mirror. If the mirror is moved further 5cm away from the object and the image is
Answer Details
When an object is placed in front of a plane mirror, the image formed is virtual and appears to be as far behind the mirror as the object is in front of the mirror. The image is upright and is the same size as the object.
In this problem, the object is initially placed 15 cm in front of the plane mirror. The image will be formed 15 cm behind the mirror, and the distance between the object and the image will be twice the distance between the object and the mirror, which is 30 cm. Therefore, the image is formed at a distance of 30 cm from the object.
If the mirror is moved 5 cm further away from the object, the new distance between the object and the mirror is 20 cm. Using the same reasoning as before, the distance between the object and the image is twice this distance, or 40 cm. Therefore, the image is now formed at a distance of 40 cm from the object.
Hence, the correct option is:
- 40 cm