An industrial step-down transformer is used to reduce the voltage from an 11 kV11\text{ kV}11 kV rms transmission line to a 230 V rms supply for a factory. When operating under full load, the transformer delivers a current of 480 A rms to the factory.
The transformer has an efficiency of 96%.
What is the rms current in the primary coil under these conditions?
9.64 A9.64\text{ A}9.64 A
10.0 A10.0\text{ A}10.0 A
10.5 A10.5\text{ A}10.5 A
10.9 A10.9\text{ A}10.9 A