A permenant magnet DC generator has a k value of 2 Wb and an RA of 13 . The primemover rotates the armature at a speed of 1000 rpm.

A permenant magnet DC generator has a kφ value of 2 Wb and an RA of 13 Ω. The primemover rotates the armature at a speed of 1000 rpm. Determine the no-load voltage, the full-load voltage,and the torque required by the prime mover at full load if the full-load power required by the load is 300W (assumming most of the power is delivered to the load) neglecting rotational losses.

I'm reading through a solution for this problem, but it makes a jump and shows the equation Ea=K*Phi*omega, and then immediately says Ea = 314.16. How is that value obtained?