(a) Define focal length of a spherical lens.
(b) A divergent lens has a focal length of 30 cm. At what distance should an object of height 5 cm from the optical center of the lens be placed so that its image is formed 15 cm away from the lens? Find the size of the image also.
(c) Draw a ray diagram to show the formation of image in the above situation.
(a) Focal length of a spherical lens is defined as the distance between optical center and focus of the lens.
(b)Given: focal length of concave lens f = -30 cm
Height of the object, h1 = 5 cm
Image distance, v = -15 cm
Applying the lens formula
Now, size of image can be calculated as follows:
(c)The ray diagram is as follows:
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