When a fork is seen through lenses A and B one by one, it appears as shown in the diagrams. What is the nature of (i) lens A, and ii) lens B? Give reason for your answer.

A parallel beam of light passes through a lens held at O as shown in Fig. What is the nature of the lens?

If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished, what is the nature of this lens ? Draw a ray diagram to justify your answer. If the numerical value of power of this lens is 10 D, what is its focal length in cartesian system ?

Classify the following functions in the form of one-one,many one,into and onto,also give reason to support your answer.

Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculation : What is the focal length of the convex lens? Give reason in support of your answer.

Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculation : What is the focal length of the convex lens ? Give reason to justify your answer.

The magnification produced by a spherical lens is +2.5 . What is the: a) nature of image? b) nature of lens?

The magnification produced by a spherical lens is +0.75 . What is the: a) nature of image? b) nature of lens?

Draw ray diagrams to represent the nature, position and relative size of the lens for the object placed: a) at 2F_(1) , b) between F_(1) and the optical center O of the lens. Which of the above two cases shows the use of convex lens as a magnifying glass? Give reasons for your choice.