How can CRJ PSU reading lights be tested?

Pushing the reading light test button on the flight attendant panel is the correct method for testing CRJ PSU (Passenger Service Unit) reading lights because this specific button is designed to activate the reading lights and allow for a quick assessment of their functionality. When the button is pressed, it individually illuminates each reading light, confirming that they are operational. This test is efficient for crew members to ensure all lighting systems are functioning properly without needing to perform individual inspections.

Other methods, such as turning off and then on the main power, toggling the ceiling lights, or checking individual reading lights manually, do not necessarily provide a systematic or reliable way to verify the operation of the reading lights. The dedicated test button is specifically intended for this purpose, making it the most effective choice.