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The image of a small electric bulb fixed...

The image of a small electric bulb fixed on the wall of a room is to be obtained on the opposite wall 3m away by means of a large convex lens. What is the maximum possible focal length of the lens required for the purpose?

Text Solution

Verified by Experts

focal length `f=("distance between the wall")/(4)`
i.e., `f=(3)/(4)=0.75m`
or `f=75cm. `
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