We have two electric dipoles. Each dipole consists of two equal and opposite point charges at the ends of an insulating rod of length $d.$ The dipoles sit along the $x$-axis a distance $r$ apart, oriented as shown in the figure.
Their separation $r\gg d.$ The dipole on the left:

In a uniformly charged dielectric sphere, a very thin tunnel has been made along the diameter as shown in figure. A charge particle $-q$ having mass $m$ is released from rest at one end of the tunnel. For the situation described, mark the correct statement(s). (Neglect gravity.)

Consider two identical charges placed distance $2d$ apart, along the $x$-axis (see figure). The equilibrium of a positive test charge placed at point $O$ midway between them is,

For the situation shown in the figure (assume $r\gg$the length of the dipole) mark out the correct statement(s).