A physics student assembles the following real-world hardware on a benchtop:
• A cylindrical dry cell that has a raised metallic button on one end and a flat metallic plate on the other.
• A glass bulb that glows when current passes through it.
• A spring-loaded device that can be pressed to complete a connection, then returns to its original position when released.
• Two identical devices, each consisting of a circular scale and a pointer; one has terminals labeled "COM" and "A," while the other has terminals labeled "COM" and "V." Both devices must be inserted into the circuit for operation.
Answer the questions that follow.
(1) Translate the physical description of each hardware item into its standard schematic symbol. Provide a brief justification for each choice based on the defining physical characteristics you are given.
(2) Using only standard schematic symbols, draw a complete diagram of a circuit that lights the bulb when the spring-loaded device is pressed, and that allows the student to read the current supplied by the dry cell and the potential difference across the bulb simultaneously. Label every component.
(3) Describe the role of conventional current in interpreting the meter readings for your circuit. In particular, explain how reversing the polarity of the dry cell would affect each meter’s numerical reading and sign, if at all.