विद्युत मोटर मुख्य रूप से किस वैज्ञानिक के नियमों के सिद्धांत पर कार्य करती है?

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?