Sir, 1) A beam of light incident on a plane mirror forms a real image on reflection. It is said that the incident beam in that case is convergent. Is it true? I think it is due to the fact that a plane mirror normally forms virtual images of real object. In order that a real image be formed by it, the object should be virtual and only a convergent beam of light can produce a virtual object. Is my argument right? 2) What is the nature of the picture seen on the screen of a pin hole camera? Is it an image or a Shadow? I think it’s an image. What do you say Sir? 3) A ray reflected successively from 2 plane mirrors inclined at a certain angle undergoes a deviation of 300 degrees. How many images are observable? I solved it in the following way: We know that the deviation produced by 2 plane mirrors inclined at an angle y is 180 + 2y. Therefore 180 + 2y = 300 y = 60 Here it is assumed that the object is placed symmetrically between the 2 inclined mirrors. We know that number of images observed = (360/y) – 1 = 5 Is it right?