A student makes a device P by using three long and narrow strips of plane mirrors inclined at ${60}^{\circ }$ to one another which enables him to see beautiful pattern made by pieces of coloured glass bangles. On the other hand, another student makes a device Q by using two plane mirrors arranged parallel to each other which helps him to see a football match clearly even when some very tall persons are sitting in front of him in the ground. What are P and Q?

Q.

A student makes a device P by using three long and narrow strips of plane mirrors inclined at ${60}^{\circ }$ to one another which enables him to see beautiful pattern made by pieces of coloured glass bangles. On the other hand, another student makes a device Q by using two plane mirrors arranged parallel to each other which helps him to see a football match clearly even when some very tall persons are sitting in front of him in the ground. What are P and Q?

Q. A device that works using the reflection of light from two plane mirrors arranged parallel to one another is:

Q.

What is the tall device which contains plane mirror and can be used to see over the heads of crowds ( say,as in a football match)

Q. A person who used a concave lens saw an image. without specs, he couldn't see an image clearly which was far away. If we place a mirror closer to him he could see a mirror (object) but he can not see an image(at a long distance) which was reflected by a mirror.Why he could not see an image clearly even though the mirror was closer to him. ?

Q.

A device which works on the reflection of light from two plane mirrors arranged parallel to one another is:

(a) electroscope

(b) kaleidoscope

(c) periscope

(d) stethoscope