SEC-B Question paper

Answer the following questions:1. A 3-ø , 300 kVA, 33 kV/415 V, delta/star connected transformer is protected by circulating current

protection scheme, find the ratio of the main CT’s assuming that a secondary current of A Corresponding to full load current in the primary. [10M]2. Explain with a neat circuit diagram of the percentage differential protection scheme to protect Y - ∆ transformer. [10M]