A stationary circular conducting loop of resistance R and constant...

The magnetic flux passing through the loop is $\Phi = B \cdot A = A B_0(1 - \cos \omega t)$.

According to Faraday's law, the induced emf $\varepsilon$ is:
$\varepsilon = -\dfrac{d\Phi}{dt} = -A B_0 \dfrac{d}{dt}(1 - \cos \omega t) = -A B_0 \omega \sin \omega t$

The power $P$ dissipated in the loop is:
$P = \dfrac{\varepsilon^2}{R} = \dfrac{(-A B_0 \omega \sin \omega t)^2}{R} = \dfrac{A^2 B_0^2 \omega^2}{R} \sin^2 \omega t$

The power $P$ varies as $\sin^2 \omega t$.
At $t = 0$, $P = 0$.
As time progresses, $\sin^2 \omega t$ increases to a maximum of $1$ and then returns to $0$ periodically. Since it is a squared quantity, the power never becomes negative.

Therefore, the graph of $P$ versus $t$ is a periodic curve that starts from zero, reaches a positive maximum, and returns to zero without ever becoming negative.

Answer: A periodic curve starting from zero at $t=0$, reaching a positive maximum, and returning to zero, never becoming negative.