1) Which of the following is the correct lens formula? A) 1v−1u=1f B) 1v+1u=1f C) v - u = f D) v + u = f Answer: Option AExplanation:In optics, the relationship between the distance of an image (v), the distance of an object (u), and the focal length (f) of the lens is given by the formula known as Lens formula. ie 1v−1u=1f