The yellow button on a Fluke multimeter is used to:

• A. Select capacitance
• B. Switch between DC and AC current
• C. Select temperature
• D. Turn on the display backlight

Answer: (A)

The main idea is that the yellow button is a secondary function control used to access capacitance measurement on many Fluke meters. When you set the dial to the capacitance range (the C symbol), pressing the yellow button activates or selects the capacitance function within that mode, sometimes toggling between units (like μF, nF, pF) or ranges. This design lets you quickly switch into measuring capacitance without changing the dial, which is why this button is associated with selecting capacitance. Avoiding confusion, note that switching DC vs AC current, temperature measurement, or turning on a display backlight are typically handled differently—by the main dial, a thermocouple setup, or a separate backlight control.