Question

Choose the correct statement(s) about a plane mirror periscope.

• A. It can be used in espionage to keep an eye on someone.
• B. The final image is laterally inverted.
• C. The final image is diminished.
• D. The final image is erect.

Answer 1

Answer: (A), (D)

The correct options are
A

It can be used in espionage to keep an eye on someone.

D

The final image is erect.

We can use a periscope to look at someone while keeping ourselves hidden as shown here. so it can be used in espionage.

It consists of two plane mirrors. The image formed in the first mirror acts as an object for the second mirror. So, lateral inversion takes place two times and that implies that in the final image there is no lateral inversion w.r.t the object. Secondly, plane mirror forms erect images, so even after two reflections, the image will be erect only. Moreover, the plane mirror keeps the size of the image intact, so the image formed will not be diminished.