EPU stands for

• A. Emergency Power Unit
• B. Emergency Processing Unit
• C. Electrical Power Unit
• D. Engine Power Unit

Answer: (A)

The concept tested is recognizing the standard expansion of the acronym in practical equipment terminology. EPU stands for Emergency Power Unit, a self-contained source designed to provide electrical power (and sometimes hydraulic power) to essential systems when the main power is lost. This is crucial for keeping vital avionics, flight controls, and instrumentation functioning long enough to land safely or to restart systems.

Why this fits best: the word “Emergency” clearly signals power is needed in a critical situation, and “Power” specifies the type of energy supplied. The term is a well-established device in aviation and hydraulics practice for bridging a loss of normal power. The other options don’t reflect common, recognized terms for this role: “Emergency Processing Unit” isn’t a standard device, “Electrical Power Unit” is too generic and lacks the emergency implication, and “Engine Power Unit” would imply a source tied to the engine rather than a standalone emergency power source.