State whether the following statements are 'true' or 'false' by writing T/F against them.

(a) A convex lens has a divergent action and a concave lens has a convergent action.

(b) A concave lens, if kept at a proper distance from an object, can form its real image.

(c) A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.

(d) A ray of light incident at the optical centre of a lens, passes undeviated after refraction.

(e) A concave lens forms a magnified or diminished image depending on the distance of an object from it.

(a) False
Reason — Convex lenses have a convergent action, not a divergent action. They converge parallel incident rays of light to a focal point after refraction, hence they are often called converging lenses.
Concave lenses, on the other hand, have a divergent action. They diverge parallel incident rays of light as if they are coming from a virtual focus point, hence they are often called diverging lenses.

(b) False
Reason — Real images are formed by convex lenses, not concave lenses. Concave lenses are used to create virtual images that are upright and diminished.

(c) False
Reason — A ray of light incident at the optical centre O of a lens, passes undeviated through the lens after refraction.

(d) True
Reason — At the optical center, the incident ray passes directly through without any change in direction. Hence, it emerges from the lens with the same direction as it had when entering the lens.

(e) False
Reason — A concave lens always forms a diminished, virtual image, regardless of the distance of the object from it.