1. The problem statement, all variables and given/known data 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 4270 V, which is obtained from a standard 122.0 V outlet by means of a transformer. If the primary coil has 23 turns, how many turns are in the secondary coil? 2. Relevant equations E=-NAcos0(B/t) V=IR I=(V-E)/R -B/T=V1/N1=V2/N2 V1/V2=N1/N2 I2/I1=N1/N2 3. The attempt at a solution I'm confused about how to do this problem. I know all those formulas but I'm not sure which one to use. I'm not sure which voltage to use and what the two voltages would be. Please help. Thanks!