A supply of 200 V can be obtained from a source of 600 V by means of a two-winding transformer or an autotransformer. The ratio of weights of conductor material in the autotransformer with respect to the two-winding transformer is _____________.
1
2 ∶ 1
2
1 ∶ 1.5
3
1.5 ∶ 1
4
1 ∶ 2