question_answer 30)

                  Both earth and moon are subject to the gravitational force of the sun. As observed from the sun, die orbit of die moon                 (a) will be elliptical.                 (b) will not be strictly elliptical because the total gravitational force on it is not central.                 (c) is not elliptical but will necessarily be a closed curve.                 (d) deviates considerably from being elliptical due to influence of planets other than earth.

Answer:

                  (b) Moon is moving under the combined gravitational pull acting on it due to Earth and the Sun.