**Concept**:

For a synchronous generator,

E = V + I_{a}Z_{s}

**Explanation**:

Given that,

X_{s} = 0.8 pu, P = 1.0 pu, upf

V = 1.1 pu, Ra = 0

Power of a non-salient pole synchronous generator can be defined as P = VI_{a} cos ϕ

1 = 1.11 × I_{a} × 1

I_{a} = 0.91 pu

E = V + I_{a}Z_{s}

= 1.11∠0 + 0.91 ∠0 × 0.8 ∠90°

= 1.319 ∠33.49

The required angle = 33.49°