4.28 Can you associate vectors with (a) the length of a wire bent into a loop, (b) a plane area, (c) a sphere? Explain.
NEETprep Answer:
(a) We cannot associate a vector with the length of a wire bent into a loop. This is because the length of the loop does not have a definite direction. (b) We can associate a vector with a plane area. Such a vector is called an area vector and its direction is represented by a normal drawn outward to the area. (c) The area of a sphere does not point in any definite direction. However, we can associate a null vector with the area of the sphere. We cannot associate a vector with the volume of a sphere.
