What is the worst-case body resistance across the torso?

• A. 300 ohms
• B. 100 ohms
• C. 600 ohms
• D. 3 ohms

Answer: (A)

Current through the body during a shock is determined by I = V / R, so the impedance of the path across the torso is a key factor in how dangerous a fault can be. For a worst-case torso path, a standard conservative value used in safety practice is about 300 ohms. This reflects a realistic estimate of the skin and tissue impedance when current travels from one hand across the chest to the other, giving a meaningful hazard level without assuming unrealistically low resistance.

Using this 300-ohm value makes the calculation tangible: at a fault voltage of 600 V, the current would be around 2 A, which is well into dangerous territory and can be life-threatening. The other options don’t fit typical torso impedance: 3 ohms is unrealistically low for a torso path, 100 ohms is lower than the standard worst-case assumption, and 600 ohms is higher, implying less current than the body would allow in a hazardous scenario.