$A$ satellite is launched into a circular orbit of radius $R$ around Earth,while a second satellite is launched into an orbit of radius $1.02 R$. The percentage difference in the time periods of the two satellites is:

In an elliptical orbit under gravitational force,in general

Two planets revolve around the sun with frequencies ${N_1}$ and ${N_2}$ revolutions per year. If their average orbital radii are ${R_1}$ and ${R_2}$ respectively,then ${R_1}/{R_2}$ is equal to:

$A$ comet (assumed to be in an elliptical orbit around the sun) is at a distance of $0.4 \, AU$ from the sun at the perihelion. If the time period of the comet is $125 \, yr$,the aphelion distance is ........... $AU$ ($AU$: Astronomical Unit).

If the distance between the earth and the sun becomes half its present value,the number of days in a year would have been

If the distance of the earth from the Sun is $1.5 \times 10^8 \, km$. Then the distance of an imaginary planet from the Sun,if its period of revolution is $2.83$ years,is $............. \times 10^8 \, km$.