question_answer

A convex lens forms a full image of the object on a screen. If half of the lens is covered with an opaque object, then:

A)  the image disappears

B)  half of the image is seen

C)   full image is seen and of same intensity

D)  full image is seen and of decreased intensity

Correct Answer: D

Solution :

                 The various rays from the object, after refraction through different parts of the lens, will still converge at the same point, only their number will be less. When half the lens is covered with an opaque object. Hence, still the full image of the object is obtained but its intensity will be less.