Which of the following is NOT correct with reference to full load testing of a single-phase transformer?
1
This test is used to determine voltage regulation of the transformer.
2
In Sumpner's test, two identical transformers are taken, in which primary windings are connected in parallel whereas secondary windings are connected in series but in phase opposition.
3
In Sumpner's test, two identical transformers are taken, in which primary windings are connected in parallel whereas secondary windings are connected in series.
4
This test is used to determine temperature rise and efficiency of the transformer.