Three students measured the focal length of a convex lens using parallel rays from distant object. All of the measured the distance between the lens and the inverted image on the screen. Student A saw a sharp image on the screen and labelled the distance as f_(1). Student B saw a slightly larger blurred image on the screen and labelled the distance as f_(2). Student C saw a slightly smaller blurred image on the screen and labelled the distance as f_(3) . What is the relation between the three measurements?

Three students measured the focal length of a convex lens using parall

1.	Three students measured the focal length of a convex lens using parallel rays from distant object. All of the measured the distance between the lens and the inverted image on the screen. Student A saw a sharp image on the screen and labelled the distance as f_(1). Student B saw a slightly larger blurred image on the screen and labelled the distance as f_(2). Student C saw a slightly smaller blurred image on the screen and labelled the distance as f_(3) . What is the relation between the three measurements?
Answer» Solution :A sharp image is FORMED at FOCUS. A slightly blurred LARGER image is formed beyond the focus and a slightly blurred SMALLER image is formed before the focus. THEREFORE, `f_(3)ltf_(1)ltf_(2))`.