Position vector is a straight line with one end fixed to a body and the other end attached to a moving point. It is used to find out where the point really is in relation to the body. When the point moves, the length and direction of the position vector will change. It is also called a radius vector or a location vector. RS Aggarwal has a lot of questions and answers, which help students practise more difficult questions so they can do better on board exams.