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SAI INTERNATIONAL SCHOOL
                                                         Class 8
                                                  Home Assignment
                                                   Subject-Physics
                                                        CH- Light
                                        Subtopic- Features of Human Eye


               INSTRUCTIONS:
                    For Assertion& Reason question follow the following directions.
               DIRECTION: Each of these questions contains an Assertion followed by Reason. Read them carefully
               and answer the question on the basis of following options. You have to select the one that best
               describes the two statements.
               (a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
               (b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
               (c) If Assertion is correct but Reason is incorrect.
               (d) If Assertion is incorrect but Reason is correct.
               (e) If Assertion & Reason both are incorrect.
                   1. Assertion: Human eye has the ability to form sharp images of objects at               1
                      different position from the eye on the retina of the eye.
                      Reason: Eye lens is of convex lens of fixed focal length.
                   2. Assertion: No image is formed at blind spot on the retina.                            1
                      Reason: There is no photosensitive cell at blind spot.
               Fill in the blanks
                   3. The ability of eye lens to adjust its focal length is called _____________.           1
                   4. An image stays on the retina for about __________ second                              1


               MCQ
                   5. The human eye can clearly see up to which distance?                                   1
                          (a) Infinity
                          (b) 1000 km
                          (c) 100 km
                          (d) 10 km
                   6. Boojho while waving his hand very fast in front of his eyes, observes that his        1
                      fingers appear blurred. What could be the reason for it?
                      a) Blind spot
                      b) Multiple reflection
                      c) Persistence of vision
                      d) Irregular reflection
                   7. The human eye cannot clearly see less than which distance?                            1
                          (a) 2.5 cm
                          (b) 25 cm
                          (c) 15 cm
                          (d) 1.5 cm
                   8. Define persistence of vision in human eye. Differentiate between sensation of
                      still pictures and movies?
                   9. Where the blind spot is present in the eye? Why a person cannot see when
                      light falls on it?
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