When current flows through a resistor, heat is produced. Which measure best reduces heat inside a computer?

• A. Reduce voltage from the power supply
• B. Increase the total resistive value in the circuit
• C. Increase the physical size of resistors
• D. Use capacitors on the output of the power supply

Answer: (A)

Heat in electronic devices comes from power that is dissipated as current flows through resistance. The power a component wastes as heat is proportional to the voltage and current it draws (P = V × I, and for a resistor P = I^2R = V^2/R). Lowering the voltage feeding the computer reduces the current through many components, which in turn lowers the total power they dissipate as heat. This makes cooling easier and helps keep temperatures down.

Increasing the total resistance would cut current, but it’s not a practical way to run a computer—it would impair performance and won’t reliably reduce heat across all components. Making resistors larger doesn’t reduce heat produced; it just changes how much heat they can handle. Adding capacitors on the output helps with voltage stability and ripple, not with reducing heat generation directly.

So, reducing the supply voltage is the most effective measure to cut heat inside a computer.