A transformer has 2,000 primary turns and 120 secondary turns. If the primary is connected to a 220 V r.m.s. a.c. mains supply, determine the secondary voltage.
Rearranging \frac{V_P}{V_S} = \frac{N_P}{N_s} gives:
V_{S}={\frac{N_{S}\times V_{P}}{N_{P}}}={\frac{120\times220}{2,000}}=13.2\,\mathrm{V}