Question

Object 7. A converging lens of focal length fis used to cast an image of an object as shown in the figure. The upper half of the lens is now covered by an opaque coating. Which of the following statements is most appropriate? (a) Upper half of the image is brighter than its lower half. (6) Lower half of the image is brighter than its upper half. (c) Entire portion of the image appears with uniformly reduced brightness. (d) Entire portion of the image appears with reduced brightness but to predict intensity distribution more information is required. 1.25f

a is ans

Answer 1

8-AO-2. Bet TOS- 262 1.25f th This is the image formation without Covering the upper half of the lens. Now, if we block the upper half of the lens, the boightoness of the image will be decrea sease to half because the intensity of the image formed a lens is directly proportional to the square of the aperture of lens. oby So, the brightness will decrease Since, in all lenses and mirrors all the points refaud and for reflect light image So, the to create the

lower half of the lens contributes in the same amount as done by the upper half. So, when we convert cover the upper half of the lens, the right will refract from the lower half of the lens and will Converge above the principal axis. in the because of the converging lens. Hence, the upper half of the than the lower half Image is brigher