Question

Why are the two mirrors in a perisscope placed parallel to each other

Answer 1

plane mirrors are used in the construction of a reflecting periscope.it works on the principal of reflection of light.it consists of a cylindrical cardboard tube bent twice at right angles. the 2 plane mirrors are fixed at the bent of the tube at an angle of 45° with the side of the tube.the parallel rays entering the cylindrical tube from the upper end from an object strike the plane mirrors at an angle of 45°.finally the reflected ray reach the eye and the image of the object can be viewed from the other end

Answer 2

Two mirrors in Periscope are placed parallel to each other,so that the ray of light emerging out of the Periscope are parallel to the rays of incident on top window of the Periscope and hence the location of the object can be seen clearly