Final answer:
A solid line with a solid circle at the end in an electrical drawing indicates a ground connection, which is a safety feature to prevent electric shock and provide a return path for current.
Step-by-step explanation:
Understanding Electrical Drawing Symbols
In electrical drawings, a solid line with a solid circle at the end typically represents a ground connection. This symbol indicates a low-resistance path directly to earth that ensures the wire is at zero volts relative to ground, making it safe to touch, even if the wire's insulation is damaged or missing. Among the available options, the correct answer is 1) Grounding. This ground connection is essential as it provides safety by preventing electric shock in case of a fault and allows the electrical system to function correctly by offering an alternative return path for the current through the earth.
The neutral wire, which forms part of the three-wire system described in the provided information, is connected to the ground at the voltage source and the user's location, thereby ensuring it remains at zero volts. This is distinct from the live/hot wire, which carries the voltage and current necessary to power appliances. The color coding for wires can vary by region, with a common exception being the ground wire, which is typically green but may also be yellow or exposed as a bare wire. In contrast, live/hot and neutral wiring may have differing colors based on local standards, and thus it's crucial to confirm the correct color code within your specific area.