Which curve depicts the variation of gravitational potential $V$ of a hollow sphere of radius $R$ with distance $r$ from its center?

The gravitational potential energy of a system of three masses $m$,$2m$,and $3m$ placed at the three vertices of an equilateral triangle of side '$a$' is:

Two bodies of masses $m$ and $M$ are placed at a distance $d$ from each other. What is the gravitational potential $V$ at the point where the gravitational field intensity is zero?

Four particles each of mass $m$ are placed at four vertices of a rectangle having side lengths $3 l_o$ and $4 l_o$. The magnitude of the gravitational potential energy of the system in units of $\frac{Gm^2}{l_o}$ is:

If $V$ is the gravitational potential due to a sphere of uniform density on its surface,then its value at the center of the sphere will be:

The gravitational potential energy of a body of mass $m$ at a distance $r$ from the center of the Earth is $U$. Express the weight of the body at this point in terms of $U$.