A convex lens is used to burn a piece of...

A convex lens is used to burn a piece of paper as shown in the figure. What is its focal length and power?

Focal length = 15cm and Power = `+6.67D`

Focal length greater than 15cm and Power = 6.67 D

Focal length less than 15cm and Power less than 6.67 D

Focal length equal to 15cm and Power is more than 6.67 D

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A parallel beam of light would converge at the focus of a convex lens and reciprocal of this distance would be the power of the lens

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