Consider a convex lens of focal length 20 centimeters. If an object is placed at a distance of 40 centimeters in front of the lens, what is the nature and position of the formed image?

💡 Solution & Explanation

According to the thin lens formula, placing an object at twice the focal length from a convex lens produces a real, inverted image of identical size at an equal distance on the opposite side. Using the lens equation where object distance is negative 40 centimeters and focal length is positive 20 centimeters yields an image distance of positive 40 centimeters. Magnification under these conditions equals negative one, confirming equal height and inversion.