187. A rectangular coil with a fixed period rotates inside a uniform magnetic field at constant speed. The magnetic field lines are perpendicular to the coil surface. Which of the following graphs correctly shows the variation of magnetic flux and induced EMF versus time in one period? (The dashed graph corresponds to the change in magnetic flux.) [Figure: Four graphs labeled (1), (2), (3), (4) showing $\phi$ and $\varepsilon$ versus $t$ over period $T$, with solid and dashed sinusoidal curves phase-shifted relative to each other.]
\textbf{187.} A rectangular coil with a fixed period rotates inside a uniform magnetic field at constant speed. The magnetic field lines are perpendicular to the coil surface. Which of the following graphs correctly shows the variation of magnetic flux and induced EMF versus time in one period? (The dashed graph corresponds to the change in magnetic flux.)
\textit{[Figure: Four graphs labeled (1), (2), (3), (4) showing $\phi$ and $\varepsilon$ versus $t$ over period $T$, with solid and dashed sinusoidal curves phase-shifted relative to each other.]}