Physics
Grade-10
Easy
Question
Focal length of one side of a biconcave lens is 76 cm. Its second focal length would measure ____ cm.
Hint:
For a biconcave lens, the distance of each focuses from the optical center is equal. So the focal length on both sides is the same.
The correct answer is: 76
Focal length of one side of a biconcave lens is 76 cm. Its second focal length would measure 76 cm.
- The biconcave lenses form two principle focuses and two centers of curvature.
- The distance of each focuses from the optical center will be equal.
- If the first focal length (f1) stays in one side, then the second focal length (f2) falls on the other side .
- Since the distances of the focuses from the optical center are the same and so, the focal length on both sides is the same.
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