In what application is pulse-width modulation commonly used?

• A. To stabilize circuit voltages
• B. To adjust the brightness of LED lights
• C. To cool electronic components
• D. To measure flow rates in pipes

Answer: (B)

Pulse-width modulation (PWM) is commonly used to adjust the brightness of LED lights. This technique works by varying the amount of time the LED is turned on versus the amount of time it is off within a fixed period. By changing the duty cycle (the proportion of time the signal is on), the perceived brightness can be controlled effectively. This method is both energy-efficient and allows for smooth transitions in brightness levels without the flickering that can occur with traditional dimming methods.

In contrast, stabilizing circuit voltages, cooling electronic components, and measuring flow rates in pipes typically involve different technologies and methods that do not primarily use PWM. While PWM can contribute to thermal management indirectly by controlling the power delivered to components, its primary and most recognized application lies in lighting and motor control, particularly in adjusting brightness and speed.