An object lies at a distance of 2f from a concave lens of focal length f. Draw a ray-diagram to illustrate the image formation.

Fill in the following blanks with suitable words:

(a) A ________ lens converges rays of light, whereas a ____ lens diverges rays of light.

(b) Lenses refract light to form images: a _______ lens can form ______ images, but a diverging lens forms only ______ images.

Things always look small on viewing through a lens. What is the nature of the lens?

Show by drawing a ray-diagram that the image of an object formed by a concave lens is virtual, erect and diminished.

Give the position, size and nature of image formed by a concave lens when the object is placed:

(a) Anywhere between optical center and infinity.

(b) At infinity.