The saturation temperature refers to the temperature at which a given amount of solute (in this case, CuSO4) will dissolve completely in a solvent (water). For CuSO4, around 100°C is the typical saturation temperature, where the solute reaches its maximum solubility in water under normal conditions.
In the system shown below, $x(t)=\sin(t)u(t)$. In steady-state, the response $y(t)$ will be 
The time constant of the network shown in the figure is 
The parallel RLC circuit shown in the figure is in resonance. In this circuit, 