The percentage increase in the energy for an artificial satellite to shift it from an orbit of radius $r$ to an orbit of radius $3 r / 2$ is

The ratio of the radii of two planets is $r$ and the ratio of accelerations due to gravity on the planets is $x$. Then the ratio of the escape velocities from the planets is

A ring has a mass $M$ and radius $R$. The distance of the point on its geometric axis from its centre at which the gravitational field is strongest is

Statement I The force of attraction due to a hollow spherical shell of uniform density on a point mass situated inside it is always positive.

Statement II The force of attraction between a hollow spherical shell of uniform density and a point mass situated outside is same just as, if the entire mass of the shell is at the centre of the shell.

Which of the following is correct?