How would you calculate the percent regulation of a power supply that measures 50 volts under a small load and 40 volts under a heavy load?

To calculate the percent regulation of a power supply, you need to determine how much the output voltage drops from a no-load or light load condition to a heavy load condition. The formula for percent regulation is:

[

\text{Percent Regulation} = \frac{V_{no-load} - V_{full-load}}{V_{no-load}} \times 100%

]

In this case, the no-load or small load voltage is 50 volts, and the full-load or heavy load voltage is 40 volts. Substituting these values into the formula gives:

[

\text{Percent Regulation} = \frac{50V - 40V}{50V} \times 100%

]

[

= \frac{10V}{50V} \times 100%

]

[

= 0.2 \times 100% = 20%

]

Thus, the correct answer is 20%, indicating that the output voltage decreases by this percentage under load conditions, reflecting the performance of the power supply. This value is critical for understanding how stable the voltage output will be under varying load conditions, which is an important aspect of power supply design and reliability.