Electrical safety principle — evaluate the statement: “Voltage, not current, determines the severity of an electric shock.” Choose the most accurate assessment based on physiology and circuit theory.

Introduction / Context:Understanding shock hazards requires both physiology and basic circuit theory. Safety standards, medical data, and engineering practice all agree that the magnitude and duration of current through the human body is the primary determinant of injury risk, with voltage acting as a driver that sets current according to the body’s impedance.

Given Data / Assumptions:

• Ohm’s law applies: I = V / R_body.
• Physiological thresholds are current-based (for example, perception, let-go, ventricular fibrillation thresholds).
• Contact duration and current path (hand-to-hand, hand-to-foot) matter.

Concept / Approach:Severity correlates with current and exposure time. Standards often cite approximate thresholds such as 1 mA (perception), 5–10 mA (pain and muscle contraction), 30 mA (respiratory effects, let-go threshold), and 50–100 mA (risk of ventricular fibrillation), depending on conditions. Voltage contributes by driving current through body resistance; dry skin may present high resistance, while wet skin drastically lowers it, increasing current for the same voltage.

Step-by-Step Solution:

Verification / Alternative check:Safety codes (e.g., IEC/IEEE guidance) set limits based on allowable touch current and energy, not a fixed “safe voltage” without context, reinforcing current-centric risk.

Why Other Options Are Wrong:

• Voltage alone determines danger: Ignores variability of body resistance and contact conditions.
• Correct only for 50/60 Hz: While frequency matters for physiological response, the core metric remains current across frequencies.
• Depends solely on footwear/humidity: These affect R_body, but current and time are still the decisive metrics.

Common Pitfalls:Believing a low voltage is always safe or a high voltage always fatal. Context (path, time, skin condition) and resulting current are key.

Final Answer:Incorrect — severity depends primarily on current through the body; voltage influences current via resistance.