In the given alternating current waveform, what does the segment PQ represent?

The equation for an alternating current is given as $X = X_0 \sin \omega t$.
In this equation:

• $X$ is the instantaneous current.
• $X_0$ is the amplitude or the peak current. This is the maximum value the current reaches from the equilibrium position (the time axis).
• $\omega$ is the angular frequency.
• $t$ is time.

Looking at the waveform diagram:

• The horizontal axis represents time ($t$).
• The vertical axis represents current ($X$).
• The equilibrium position for the current is at $X=0$.
• Point P is the peak of the positive half-cycle.
• The distance from the time axis (where current is 0) to the peak (P) represents the amplitude.
• The segment PQ on the graph represents this vertical distance from the time axis (Q) to the peak current (P).

Therefore, PQ represents $X_0$.

The final answer is $\text{C. PQ}$.