Which of the following processes involves the principle of electrostatic induction?

$A$ positively charged thin metal ring of radius $R$ is fixed in the $xy$-plane with its centre at the origin $O$. $A$ negatively charged particle $P$ is released from rest at the point $(0, 0, z_0)$,where $z_0 > 0$. Then the motion of $P$ is:

Under the influence of the Coulomb field of charge $+Q$,a charge $-q$ is moving around it in an elliptical orbit. Find out the correct statement$(s)$.

Two identical charged particles,each having a mass $10 \, g$ and charge $2.0 \times 10^{-7} \, C$,are placed on a horizontal table with a separation of $L$ between them such that they stay in limiting equilibrium. If the coefficient of friction between each particle and the table is $0.25$,find the value of $L$ in $cm$. [Use $g = 10 \, m/s^2$]

$A$ particle of mass $2\,g$ and charge $1\,\mu C$ is released from a distance of $1\,m$ from a fixed charge of $1\,mC$. What will be the velocity of the particle at a distance of $10\,m$ from the fixed charge (in $m/s$)?

Two point charges $Q$ and $-Q/4$ are separated by a distance $x$. Then: