Physics-
General
Easy
Question
A convex lens of focal length f and a plane mirror are y distance apart. An object O is kept on the principal axis of the lens at a distance x from the lens. The values of x and y for the final image of O to fall exactly (position & size) on the object ‘O’
- x = f, y = f
- x = f, y = 2f
- x = 2f, y = f
- x = 2f, y = 2f
The correct answer is: x = 2f, y = 2f
This question should be solved by directly substituting the options If x = f, y = f then final image will be formed as shown.
For option B and C the position of image will be different. When x = 2f, y = 2f, the lens makes image I¢ of object O on the surface of mirror as shown in the figure. Mirror shall make of image of I¢ over I¢ itself. Hence lens shall make image of I¢ at the position of O. (which is I )
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