50. 51. 52. Under what condition in an arrangement of two plane mirrors, incident ray and reflected ray will always be parallel to each other, whatever may be angle of incidence. Show the same with the help of diagram. It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm. i. What should be the range of distance of an object placed in front of the mirror? ii. Will the image be smaller or larger than the object? Draw ray diagram to show the formation of image in this case. iii. Where will the image of this object be, if it is placed 24 cm in front of the mirror? Draw ray diagram for this situation also to justify your answer. Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams. An object 1 cm high is placed on the axis and 15 cm from a concave mirror of focal length 10 cm. Find the position, nature, magnification and size of the image. 53. a. List four characteristics of the images formed by plane mirrors. b. A 5 cm tall object is placed at a distance of 20 cm from a concave mirror of focal length 30 cm. Use mirror formula to determine the position and size of the image formed.