A positive point charge $+Q$ is fixed in space. A negative point charge $-q$ of mass $m$ revolves around fixed charge in an elliptical orbit. The fixed charge$+Q$ is at one focus of the ellipse. The only force acting on the negative charge is the electrostatic force due to the positive charge. Then which of the following statement is true?

Select the correct statement(s) with respect to charges.

A large non-conducting sheet $M$ is given a uniform charge density. Two uncharged small metal rods $A$ and $B$ are placed near the sheet as shown in figure.

An uncharged conducting ball $B$ lies inside a charged conductor $A$ as shown in the figure. $B$ is isolated from $A$.

A point charge $q$ is within an electrically neutral conducting shell whose outer surface is a sphere of radius $R$. The centre of outer surface is at $O$. Consider a point $P$ outside the conductor as shown in the figure. The magnitude of electric field at $P$