A magnetic field is perpendicular to a 0.0387 m x 0.0599 m rectangular coil of wire that has 109 turns. In a time of 0.0525 s, an average emf of magnitude 1.66 V is induced in the coil. What is the magnitude of the change in the magnetic field?
A neon sign requires 10000 V for its operation. It operates from a 220 V receptacle. What must be the turns ratio Ns/Np of the transformer?
In some places, insect "zappers", with their blue lights, are a familiar sight on a summer's night. These devices use a high voltage to electrocute insects. One such device uses an ac voltage of 4360 V, which is obtained from a standard 120 V outlet by means of a transformer. If the primary coil has 18 turns, how many turns are in the secondary coil?