A parallel plate capacitor of capacitance \( 200 \, \mu \text{F} \) is connected to a battery of \( 200 \, \text{V} \). A dielectric slab of dielectric constant \( 2 \) is now inserted into the space between plates of capacitor while the battery remain connected. The change in the electrostatic energy in the capacitor will be _______ \( \text{J} \).
