question_answer 47)

      Consider an extended object immersed in water contained in a plane through. When  seen from close to the edge of the trough, the object looks distorted because                  (a) the apparent depth of the points close to the edge are nearer the surface of the water compared to the points away from the edge. (b) the angle subtended by the image of the object at the eye is smaller than the actual angle subtended by the object in air. (c) some of the points of the object far away from the edge may not be visible because of total internal reflection. (d) water in a trough acts as a lens and magnifies the object.

Answer:

      (a,b,c) Here, an extended object lies immersed in water contained in a plane trough. When seen from close to the edge of the trough, the object looks distorted on account of refraction of light from denser to rarer medium. Therefore, apparent depths of the points close to the edge and nearer to the surface of water is more compared to points away from the edge. Further, the angle subtended by the image of the object at the eye is smaller than the actual angle subtended by the object in air. Again, some of the points of the because of total internal reflection. The choices (a), (b), (c) are correct.