A coin is placed 20 cm in front of a two-lens system. Lens 1 (nearer the coin) has focal length f1 =+10 cm, lens 2 has f2 =+12.5 cm, and the lens separation is d = 30 cm. For the image produced by lens 2, what are (a) the image distance i2 (including sign), (b) the overall lateral magnification, (c) the image type (real or virtual), and (d) the image orientation (inverted relative to the coin or not inverted)?

= 1.0). An object (A) is Assume that a thin lens (r, placed in the left side of lens (d = 45mm) and the image of the object is located in the right side of the lens at position (B) (d' = 90mm). 1) Compute the refraction index of the lens (n2); = -r2 = 40mm) is placed in the air (n 2) If placing another negative thin lens (f2 = -180mm) immediately behind the first lens to create a doublet lens in which the spacing between two lenses is zero (as shown in the right figure), what is the focal length of this doublet? 3) Where is the final image position (C) of the object (A) through this new doublet? (Note: Assuming this doublet lens is a combined thin lens too without considering its thickness).

= A doublet lens consists of two lenses in effective contact. The front lens is biconvex with fi +37.5 cm, and the second is biconcave with f2 = -150 cm. An object of height 2 cm is placed at 80 cm to the left of the combined lens. Calculate the position of the image, and the image height.

A student with normal sight is surprised to see a possum scampering up the rear wall in the Lyle theatre. The possum is 30.0 cm long and the wall is 2.3 m away. The student's eyeballs have a diameter of 2.4 cm. How big is the image of the possum on the student's retina? (Units: cm)