Question

Student obtains a blurred image of a distant object on a screen using a convex lens. To obtain a distinct image on the screen he should move the lens.
A.)Away from the screen
B.)Towards the screen
C.)To a position very far from the screen
D.)Either towards or away from the screen depending upon the position of the object

Answer 1

Hint: We will consider different cases of image formation by a convex lens and will conclude whether the lens should be moved towards the screen or away from the screen to get a distinct image of the object.

Complete step by step answer:
The convex lens is a type of lens that converges the rays of light that convey parallel to its principal axis. Convex lens is relatively thick across the middle and thin at the lower and upper edges. The edges of the lens are curved outwards.

Image formation by Convex lens:

Object location	Ray diagram	Image location	Image nature	Image size
Infinity		At ${{\text{F}}_{\text{2}}}$	Real and Inverted	Diminished
Beyond $\text{2}{{\text{F}}_{\text{1}}}$		Between ${{\text{F}}_{\text{2}}}$and $\text{2}{{\text{F}}_{\text{2}}}$	Real and Inverted	Diminished
At $\text{2}{{\text{F}}_{\text{1}}}$		At $\text{2}{{\text{F}}_{\text{2}}}$	Real and Inverted	Same size
Between ${{\text{F}}_{\text{1}}}$and $\text{2}{{\text{F}}_{\text{1}}}$		Beyond $\text{2}{{\text{F}}_{\text{2}}}$	Real and Inverted	Enlarged
At ${{\text{F}}_{\text{1}}}$		At Infinity	Real and Inverted	Enlarged
Between $\text{O}$and ${{\text{F}}_{\text{1}}}$		On the same side as the object	Virtual and Erect	Enlarged

When an object is moved closer to the convex lens, we obtain a distinct, well illuminated, and enlarged image of the object.

To obtain a distinct image of an object on the screen, students should have to move the lens towards the screen. Second focus of the lens will behave as a screen. When an object is placed at infinity, image is obtained at the focus of the lens.
Hence, the correct option is B.

Note:
Convex lens, or converging lens, can produce both real and virtual images. The size of the image varies according to the position of the object. As we move objects close to the lens, we obtain a well-defined and magnified image of the object.