In a parallel LCR circuit, the current at resonance will be

Two pendulums $C$ and $D$ are suspended from a wire as shown in the given figure. Pendulum $C$ is made to oscillate by displacing it from its mean position. It is seen that $D$ also starts oscillating. What is the name of the phenomenon when the length of $D$ is made equal to $C$?

Two pendulums $C$ and $D$ are suspended from a wire as shown in the given figure. Pendulum $C$ is made to oscillate by displacing it from its mean position. It is seen that $D$ also starts oscillating. Name the type of oscillation, $D$ will execute.

If the differential equation is given by

$\frac{d^{2}y}{d{t}^2}+2k\frac{dy}{dt}+{\omega }^{2}y=F_0\mathrm{si}\mathrm{n}pt$

Describes the oscillatory motion of the body in a dissipative medium under the influence of a periodic force, then the state of maximum amplitude of the oscillation is a phenomenon of