SSC JE Electrical Engineering 2017 Set 2 Paper

Load carried by V–V or Delta connection is 57.7% of original load. In V–V connection one winding is opens circuit in Delta connection.Power rating of open Delta = $\sqrt{3}{\mathit{V}}_{{\mathrm{P}}_{\mathit{n}}}{\mathit{I}}_{{\mathrm{P}}_{\mathit{n}}}$
So and power creating of Delta – Delta $=3{\mathit{I}}_{{\mathrm{P}}_{\mathit{n}}}{\mathit{V}}_{{\mathrm{P}}_{\mathit{n}}}$
Then = $\frac{\sqrt{3}{\mathit{V}}_{{\mathrm{P}}_{\mathit{n}}}{\mathit{I}}_{{\mathrm{P}}_{\mathit{n}}}}{3{\mathit{I}}_{{\mathrm{P}}_{\mathit{n}}}{\mathit{V}}_{{\mathrm{P}}_{\mathit{n}}}}$ = 57%