What is the minimum amperage required to potentially stop a human heart?

The correct answer is based on the understanding of electrical current and its effect on human physiology. Studies and safety guidelines suggest that a current of around 100 to 300 milliamperes (mA) passing through the human body can induce serious effects, including potentially stopping the heart. Thresholds vary depending on individual factors such as the person's health, resistance of their skin, and the path the current takes through the body.

The choice of 250mA aligns well with recognized safety standards and educational resources that indicate significant risk of cardiac arrest at this level of current. Current greater than 100mA is where ventricular fibrillation, a condition that can lead to cardiac arrest, becomes a serious concern. While 125mA may pose risks, 250mA is on the higher end where immediate medical intervention would likely be necessary. The idea of 500mA is even more concerning, but 250mA is the minimum threshold considered particularly dangerous.

In summary, 250mA is widely recognized as a critical threshold at which there is a high risk of inducing life-threatening conditions in a person, notably affecting the heart's normal rhythm.