The concept required to solve the given problem is lens formula and power of lens.
Initially, find the focal length of lens using equation . In the next step, find the power of lens using equation .
The expression for the lens equation is given as follows:
Here, f is the focal length of lens, v is the image distance and u is the object distance.
The power of the lens is,
The object distance from the glass is,
The image distance from the lens is,
The screen will produce a virtual image at a distance of 120 cm from the eye. Thus, the image distance is negative.
Substitute 53 cm for u and -118 cm for v in equation .
Substitute 96.12 cm for f in equation .
Ans:
The power of lens is 1.04 D.
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