Two coils L1 and L2 having number of turns N1 = 2 and N2 = 1 respectively are wound on the same core. What is the ratio of their inductances L1L2?

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?