Which action would minimize heating effects of a current in a circuit?

• A. Lower current
• B. Increase voltage
• C. Add a lamp
• D. Increase resistance of a resistor

Answer: (A)

Heat from an electric current comes from power dissipated in resistive parts, which is proportional to the square of the current: P = I^2R. This means that reducing the current directly lowers how much heat is produced. Lowering the current is the most straightforward way to minimize heating because it cuts the heat released in the circuit immediately and more dramatically than changing other aspects. (If you raise resistance while keeping the supply the same, the current would fall and heat would drop too, but that changes the circuit conditions rather than directly reducing the current.)