The power of a convex lens is 4D. An object is placed at a distance of 25cm in front of the lens. Find the position of image.0∞∞25 cm-25 cm

The power of a lens is given by the formula:

P = 1/f

where P is the power of the lens and f is the focal length. The power of the lens is given in diopters (D) and the focal length is given in meters.

Given that the power of the lens is 4D, we can find the focal length by rearranging the formula to:

f = 1/P

Substituting the given power into the formula gives:

f = 1/4 = 0.25 meters = 25 cm

The lens formula is given by:

1/f = 1/v - 1/u

where f is the focal length, v is the image distance, and u is the object distance. We are given that the object is placed 25 cm in front of the lens, so u = -25 cm (the negative sign indicates that the object is on the same side of the lens as the light source).

Substituting the given values into the lens formula gives:

1/25 = 1/v - 1/-25

Solving this equation for v gives:

1/v = 1/25 + 1/25 = 2/25

Therefore, v = 25/2 = 12.5 cm

The positive sign indicates that the image is formed on the opposite side of the lens from the light source. Therefore, the image is formed 12.5 cm from the lens.