Interactive Transformer Diagram / Calculator
On this page -
http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/keeping_things_moving/transformers/revision/3/
Then on the following page on that site -
Conservation of energy in transformers
http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/keeping_things_moving/transformers/revision/4/
Quote from that page "The secondary coil has a 4.0 A current flowing through it. "
- It is as if they just state "4.0 A current" to maintain "Conservation of energy"