1. A spherical mirror produces an image of magnification -1 on a scree...
Concave Mirror and Image Formation
Concave mirrors are mirrors that curve inward and can either produce real or virtual images depending on the position of the object relative to the mirror. When an object is placed beyond the focal point of a concave mirror, it produces a real inverted image. On the other hand, when the object is placed between the focal point and the mirror, it produces a virtual erect image.
Given Information
- Magnification (m) = -1
- Distance of the screen from the mirror (d) = 50 cm
Finding the Distance of the Image
The magnification is given as -1, which indicates that the image is of the same size as the object but inverted. Using the formula for magnification (m = -v/u), where v is the image distance and u is the object distance, we can find the distance of the image for the object.
m = -1 = -v/u
-1 = -v/(-u)
v = u
Therefore, the distance of the image is equal to the distance of the object, which is 50 cm.
Ray Diagram
To draw the ray diagram, we first draw the principal axis and mark the focal point (F) and the center of curvature (C) on the concave mirror. Then, we draw the incident ray parallel to the principal axis, which will pass through the focal point after reflection, and the ray passing through the focal point, which will be reflected parallel to the principal axis. The intersection of these two rays will give the inverted image of the object at a distance of 50 cm from the mirror.
Focal Length
The focal length of a concave mirror is negative, as it is a converging mirror. It is equal to half of the radius of curvature of the mirror. In this case, since the image distance is equal to the object distance, the focal length can be calculated using the formula for the mirror equation (1/f = 1/v + 1/u).
Therefore, the focal length of the concave mirror in this case is -25 cm.
To make sure you are not studying endlessly, EduRev has designed Class 10 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 10.