The magnetic flux through a loop increases according to the relation φB(t) = 10t2 + 20t, where φB is in milliwebers and t is in seconds. The magnitude of current through a resistor of R = 2 Ω at t = 5 s is ________ mA.

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?