What is the path of the particle which is moving in the $x-y$ plane, such that the sum of it's distances from two fixed points $A(2,0)$ and $B(-2,0)$ is always constant ?

A small satellite is in elliptical orbit around the earth as shown in figure. $L$ denotes the magnitude of its angular momentum and $K$denotes its kinetic energy. If $1$ and $2$ denote two positions of the satellite, then

A planet revolving in elliptical orbit has :

A. a constant velocity of revolution.

B. has the least velocity when it is nearest to the sun.

C. its areal velocity is directly proportional to its velocity.

D. areal velocity is inversely proportional to its velocity.

E. to follow a trajectory such that the areal velocity is constant.

Choose the correct answer from the options given below:

A planet is revolving around the sun in which of the following is correct statement?

India's Mangalyan was sent to the Mars by launching it into a transfer orbit EOM around the sun. It leaves the earth at $E$ and meets Mars at $M$. If the semi-major axis of Earth's orbit is ${\text{a}}_{\text{e}}=\text{1.5}\times 10^{11}\text{m}$ , that of Mar's orbit ${\text{a}}_{\text{m}}=\text{2.28}\times 10^{11}\text{m}$, taking Kepler's laws, give the estimate of time for Mangalyan to reach Mars from Earth.

A planet revolves in an elliptical orbit around the sun. The semi-major and semi-minor axes are $a$ and $b$. Then, the square of time period $T$ is directly proportional to-

A star mass $M$ (equal to the solar mass) with a planet (much smaller than the star) revolves around the star in a circular orbit. The velocity of the star with respect to the centre of mass of star-planet system is shown below:

The radius of the planet's orbit is closest to ($1 \mathrm{AU}=\mathrm{Distance} \mathrm{Earth} \mathrm{and} \mathrm{Sun}$)