Where a pen is placed in front of convex lens of image is equal to size of pen what will be power of lense indioptres?

If the image of the pen is the same size as the pen when placed in front of a convex lens, then it is at the focal point of the lens. The power of the lens in diopters is given by the formula: ( P = \frac{1}{f} ), where ( f ) is the focal length of the lens in meters. With the image distance being equal to the focal length, the power of the lens will be 1 diopter.