A parallel-plate capacitor is completely filled with a dielectric slab of dielectric constant \(\kappa > 1\) and charged by a battery of potential difference \(V_0\). In Scenario 1, the capacitor is disconnected from the battery, after which an external agent slowly withdraws the slab until it is completely removed, requiring mechanical work \(W_1\). In Scenario 2, the capacitor remains connected to the battery while the external agent slowly withdraws the slab until it is completely removed, requiring mechanical work \(W_2\). What is the ratio \(\dfrac{W_1}{W_2}\)?