A 3-phase 900 kVA, 3 kV / $$\sqrt 3 $$ kV (Δ/Y), 50 Hz transformer has primary (high voltage side) resistance per phase of 0.3 Ω and secondary (low voltage side) resistance per phase of 0.02 Ω. Iron loss of the transformer is 10 kW. The full load % efficiency of the transformer operated at unity power factor is _______ (up to 2 decimal places).

In a salient pole synchronous motor, the developed reluctance torque attains the maximum value when the load angle in electrical degrees is

The equivalent circuit of a single phase induction motor is shown in the figure, where the parameters are

R₁ = R₂^' = X_l1 = X_l2^' = 12 $$\Omega $$, X_m = 240 $$\Omega $$

and s is the slip. At no-load, the motor speed can be approximated to be the synchronous speed. The no-load lagging power factor of the motor is___________ (up to 3 decimal places).

A positive charge of 1 nC is placed at (0, 0, 0.2) where all dimensions are in metres. Consider the x - y plane to be a conducting ground plane.

Take $${\varepsilon _0} = 8.85 \times {10^{ - 12}}$$ F/m.

The Z component of the E field at (0, 0, 0.1) is closest to