What is the rating of the auxiliary battery in the secondary electrical system?

The correct answer is that the rating of the auxiliary battery in the secondary electrical system is 24 VDC, 5 amp/hour. This battery provides emergency power to critical systems and equipment in the aircraft when the main electrical systems are inoperative or if there is a failure in power supply.

Understanding this specification is essential for operations, as it highlights the voltage and capacity of the auxiliary power source, ensuring that pilots can adequately manage electrical load during flight. A 24 VDC rating aligns with standard practices and needs for aviation, while the 5 amp/hour capacity indicates the duration and amount of current the battery can provide under load, which is suitable for the auxiliary functions it serves.

The other options reflect different voltages and capacities that do not match the specifications for the T-6B's auxiliary battery, thereby being inconsistent with the aircraft's design and operational requirements.