A circuit diagram could be related to a closed circuit if the diagram is of a closed circuit.

The drawing of an electrical circuit is called a circuit diagram, or schematic diagram. It is a graphical representation of the electrical components and their interconnections in a circuit. It uses standardized symbols to represent different components such as resistors, capacitors, transistors, switches, and wires. The lines connecting the symbols in the diagram indicate the flow of electrical current through the circuit. Circuit diagrams are used to design, troubleshoot, and repair electrical systems, and can be found in technical manuals, books and online resources.

sensing amplifiers and its circuit diagram

There is no "proper name" for an electrical diagram. They are commonly called circuit diagrams.

diagram in series lcr circuit