Ans: Since the value of gravitational acceleration is different in different places in Earth, so the weight of object is different in different places in Earth. Since the Earth is not completely spherical and is slightly pressed in the polar region so radius of Earth (R) is not constant. Since radius of Earth (R) is the lowest in the polar region so the value of g is the most there. As a result, weight of object is the maximum there. Again, since radius of Earth R is the maximum in the equator so the value of g is the minimum there. This is why weight of object is the minimum in the equator. Besides, the act of height and diurnal motion cause the variation in the values of g which causes the variation in the weight of object.