Considering a practical transformer, We can get a given voltage and corresponding current ratio by selecting a particular turns ratio. ie. V1/V2=N1/N2=i2/i1 Say that I want to make a 240V/60V. Now 240/60 volts ratio can be acheived by considering different no. of turns on primary(P) and secondary(S). like: 1)P=4 turns ,S=1 turn 2)P=24 turns,S=6 turns 3)P=120 turns ,S=30 turns 4)P=240 turns,S=60 turns 5)P=4800 turns S=1200 turns So we have various options for a given voltage ratio.So will each of the above turns ratio work? Then why do we have 230-60V / or 230-12V transformers so bulky.How does current rating affect no. of turns?