$A$ planet of mass $m$ is moving in an elliptical orbit about the sun with time period $T$. If $A$ is the area of the orbit,then its angular momentum is:

Let the speed of the planet at the perihelion $P$ in the figure be $v_{P}$ and the Sun-planet distance $SP$ be $r_{P}$. Relate $\{r_{P}, v_{P}\}$ to the corresponding quantities at the aphelion $\{r_{A}, v_{A}\}$. Will the planet take equal times to traverse $BAC$ and $CPB$?

When a satellite moves around the earth in a certain orbit,the quantity which remains constant is:

Match Column-$I$ with Column-$II$.

Column-$I$	Column-$II$
$(1)$ Kepler's first law	$(a)$ Law of periods
$(2)$ Kepler's second law	$(b)$ Law of orbits
$(3)$ Kepler's third law	$(c)$ Law of areas

The motion of satellites in the solar system is an example of which of the following?

Two planets are at mean distances $d_1$ and $d_2$ from the sun,and their orbital frequencies are $n_1$ and $n_2$ respectively. Then: