Answer the following questions.
(a) How many times is an image in a plane mirror bigger or smaller than the object?
(b) Where is the image formed in a plane mirror located?
(c) Explain the difference between regular and irregular reflection.
(d) How many images are obtained in two parallel mirrors?
(e) Why are the two mirrors in a periscope placed parallel to each other?
(a) Size of the image formed by the plane mirror is always same as the size of the object.
(b) The image formed in a plane mirror is located at the same distance of the object from the mirror.
(c) Regular reflection takes place from a smooth or a regular surface. In regular reflection, all reflected rays are parallel to each other for parallel incident rays.
Irregular reflection takes place from an irregular surface. In irregular reflection, the reflected rays are not parallel to each other for parallel incident rays. This happens because of the presence of irregular microscopic surfaces. Hence, parallel incident rays reflect in different directions.
However, each ray obeys the laws of reflection. Therefore, laws of reflection are not violated in diffused or irregular reflections.
(d) Infinite number of the images are obtained in two parallel mirrors.
(e) The two mirrors are placed parallel to each other in a periscope so that we get a clear image of an object. In this, image formed by upper mirror is reflected into the lower mirror. If they are not parallel then image formed by the upper mirror is not properly reflected into the lower mirror, and we see an unclear image of the object in the lower mirror.