Question

In an orbital motion, the angular momentum vector is

• A. along the radius vector
• B. parallel to the linear momentum
• C. in the orbital plane
• D. perpendicular to the orbital plane

Answer 1

Answer: (D)

perpendicular to the orbital plane

Answer 2

If a body is rotating about a given axis, then the sum of the moments of the linear momentum of all the particles is known as the angular momentumof the body about that axis.

$J=I \omega=m r v$

Since the direction of velocityis perpendicular to the orbital plane $J \propto v$, hence, in an orbital motion, the angular momentum vector is perpendicular to the orbital plane.