Answer
(a) $b_A=0, b_B=\frac{5\pi}{4}$, $b_B-b_A=\frac{5\pi}{4}$
(b) No. $\frac{5\pi}{4}$
Work Step by Step
(a) The standard form of the equation is $y=Asin(kt-b)$ where $b$ is the phase.
Compare each equation with the standard form, we can obtain the phases $b_A=0, b_B=\frac{5\pi}{4}$ and the phase difference is $b_B-b_A=\frac{5\pi}{4}$
(b) As the phase difference is not zero, the voltages are not in phase. Clearly, if we rotate the armature of the second generator counterclockwise by an angle of $\frac{5\pi}{4}$, its new phase would be $b_B=0$ and the voltages produced by the two generators will be in phase.
