A Francis turbine has the following dimensions: r1 = 4.5 m, r2 = 2.5 m, b1 = b= 0.85 m, b1 = 75°, b2 = 100°. The angular speed is 120 rpm, and the discharge is 150 m3 /s. For no separation at the entrance to the runner, determine the guide vane angle, theoretical torque, head, and power.