Heat limits _______________

• A. Voltage
• B. Current flow
• C. Power
• D. Efficiency

Answer: (B)

Heat determines how much current a conductor can carry safely because current generates heat in the material. The heat produced is P = I^2R, so as current increases, the temperature rises. If the heat isn’t dissipated quickly enough, the temperature reaches the insulation or material limits and reliability suffers or components fail. That’s why the safe current is set by thermal constraints rather than by voltage, power, or efficiency. Voltage can influence current via resistance, and power relates to how much heat is produced, but the actual limiter is how much heat the system can safely handle.