Question

Your school laboratory has one large window. To find the focal length of a concave mirror using one of the walls as screen, the experiment maybe performed on
(a) On the same wall as the window
(b) On the wall adjacent to the window
(c) on the wall opposite to the window
(d) only on the table as per laboratory arrangment

Answer with an explanation. (CBSE 2017)

Answer 1

Answer:

(a) on the wall.to. Window

Answer 2

To find the focal length of a concave mirror using one of the walls as a screen, the experiment maybe performed a) On the same wall as the window.

• The experiment may be performed on the same wall as the window to obtain a sharp image because a concave mirror forms an image on the same side of the object.
• Since the object is far away, the light rays coming from the object is parallel. Parallel rays converge at the focal length of the concave mirror.