A step-up transformer has 300 turns on the primary coil and 90000 turns on the secondary coil if the current flowing through the secondary is 5 amps what is the current flowing in the primary?

If a step-up transformer has 200 turns on the primary coil and 3000 turns on the secondary coil, with a primary coil voltage of 90 volts and current of 30 amps, then the turns ratio is 200:3000, so the secondary voltage is 1350 voltage and the available current is 2 amps. (This ignores losses through the transformer.)