Current flow as low as how many milliamps can produce a physical sensation?

• A. 0.5 mA
• B. 1 mA
• C. 2 mA
• D. 5 mA

Answer: (B)

The important idea is the threshold at which electrical current becomes perceptible when it passes through the body. For typical alternating current exposure (like what you’d encounter with practical electrical safety questions), about one milliamp is enough for most people to feel something—a faint tingling or sensation.

Below that level, such as 0.5 mA, many people do not notice anything. As current increases, the sensation becomes more noticeable; at around 2 mA you’d feel a stronger tingling, and at higher levels it can cause more pronounced sensations or involuntary responses. If direct current were involved, a higher current is usually required to produce the same perceptible effect.

So, the smallest current that can produce a physical sensation under common AC conditions is about 1 mA, making that the best choice.