Construction of current transformer:
C.T. has bar type conductor, which behaves as primary winding. The primary of C.T. carries large current Ip which is to be measured, so the bar is of large cross sectional area. The secondary of C.T.is made up of large number of turns. It is wound on core. The secondary winding is a low current winding. Hence its cross sectional area is small. An ammeter of small range is connected across the secondary as shown in figure.