Answer
(a) $\pi$ rad or $180^{\circ}$
(b) $\pi/2$ rad or $90^{\circ}$
(c) $3\pi/2$ rad or $270^{\circ}$
Work Step by Step
(a) The phase difference between the two waves $A$ and $B$ in radians is $\pi$ and in degrees is $180^{\circ}.$ Hence, the shift from $A$ to $B$ is
$\pi$ rad or $180^{\circ}.$
(b) The phase difference between the two waves $A$ and $B$ in radians is $\pi/2$ and in degrees is $90^{\circ}.$ Hence, the shift from $A$ to $B$ is
$\pi/2$ rad or $90^{\circ}.$
(c) The phase difference between the two waves $A$ and $B$ in radians is $3\pi/2$ and in degrees is $270^{\circ}.$ Hence, the shift from $A$ to $B$ is
$3\pi/2$ rad or $270^{\circ}.$
