Answer
The charge on the capacitor increases.
Work Step by Step
When a dielectric is inserted in a capacitor, the dielectric increases the capacitance of the capacitor.
The capacitance increases.
Because the capacitance of the capacitor with the dielectric increases, the equivalent capacitance of the two capacitors also increases.
Since the potential difference across the circuit remains the same, the charge must increase, since in general $~~q = CV$
The charge on the capacitor increases.
