Physics Question from JEE Main 2025 · 8 April, Shift 2

Space between the plates of a parallel plate capacitor of plate area $4 \, \text{cm}^2$ and separation of $d = 1.77 \, \text{mm}$, is filled with two uniform dielectric slabs stacked one above the other, each covering the full plate area and each of thickness $d/2$: the slab of dielectric constant $5$ lies against the upper plate and the slab of dielectric constant $3$ lies against the lower plate. Another capacitor of capacitance $7.5 \, \text{pF}$ is connected in parallel with it. The effective capacitance of this combination is _____ $\text{pF}$.

(Given $\varepsilon_0 = 8.85 \times 10^{-12} \, \text{F/m}$)