What level of voltage in an AC system is considered dangerous?

The level of voltage in an AC system that is typically considered dangerous is 50 Volts AC and above. Voltages at this level can pose serious risks of electric shock or electrocution, especially in wet or conductive environments where the human body's resistance to electric current is significantly lowered.

The choice citing 15 Volts AC does not represent a commonly recognized threshold for danger in terms of electrical safety. Generally, while lower voltages can be less hazardous, there is still a risk associated with any voltage depending on the specific conditions and circumstances, but it is the 50-volt standard that is widely acknowledged for electrical systems.

In practical scenarios, voltages above 50 Volts AC are usually the focus of safety regulations, training, and standards because they are more likely to cause injury or fatality. Thus, understanding these safety thresholds is crucial for anyone working with or around electrical systems.