A parallel-plate capacitor has plates of area $100\ \text{cm}^2$, $6.0\ \text{mm}$ apart, and a $120\ \text{V}$ battery stays connected across it. An uncharged metal slab $2.0\ \text{mm}$ thick, as large as the plates, is held inside on insulating supports, parallel to the plates. It is $1.0\ \text{mm}$ from the positive plate and $3.0\ \text{mm}$ from the negative plate, as in the figure. The supports carry no charge, and the slab touches neither plate. Ignore the effects at the edges. Take $\varepsilon_0 = 8.85 \times 10^{-12}\ \text{C}^2\,\text{N}^{-1}\,\text{m}^{-2}$. Which of the following statements are correct?

Fig. 1: Side view of a parallel-plate capacitor with plates 6.0 mm apart, each of area 100 square centimetres, joined to a 120 V battery, the left plate positive. A metal slab 2.0 mm thick stands inside, parallel to the plates, 1.0 mm from the positive plate and 3.0 mm from the negative plate. The gaps are drawn wider than to scale.