Final answer:
The minimum safe distance to keep metal tools and equipment from a high-voltage work area is generally recommended as around 10 feet, though the specific minimum was not provided in the choices. The practice of working 'one-handed' with high-power electric circuits is advised to reduce the risk of electrical current passing through the heart.
Step-by-step explanation:
When working with high-voltage circuits or around wires having exposed surfaces, one should keep tools and equipment that have metal parts at least 10 feet away from the work area. This is not specified in the presented options, and without the proper context or source, a definitive answer from the provided choices can't be given. However, the Occupational Safety and Health Administration (OSHA) generally recommends that conductive materials and equipment be kept at a safe distance, often around 10 feet, from energized electrical equipment.
As to why it's sensible to work "one-handed" or to "keep one hand in your pocket" when working with high-power electric circuits, this practice minimizes the risk of electrical current passing through the heart. Since our bodies are good electrical conductors, especially when we are in contact with a voltage source and ground, it is important to avoid creating a circuit through the body. Working with one hand reduces the possibility of current flowing through vital organs, especially the heart, should an accidental contact with an energized conductor occur.
Wearing insulated shoes, for example, is another precaution since they provide resistance and inhibit a pathway to ground which prevents electric shocks. Also, when a person is wet, their body resistance to earth/ground significantly decreases, increasing the risk of electric shock, as depicted in the safety calculations presented in theoretical problems.