A 10V source of internal resistance 10 Ω is to be connected to a load of 40 Ω through a transformer. For maximum power transfer, the turns ratio of the transformer should be:

A step-down transformer connected to an AC mains supply of 220 V operates an 11 V, 44 W lamp. Ignoring power losses, what is the current in the primary circuit?

A transformer has 200 turns in its primary winding and 1000 turns in its secondary winding. What type of transformer is this?