A parallel-plate capacitor of capacitance 40μF is connected to a 100 V power supply. Now the intermediate space between the plates is filled with a dielectric material of dielectric constant K = 2. Due to the introduction of dielectric material, the extra charge and the change in the electrostatic energy in the capacitor, respectively, are -
1
2 mC and 0.2 J
2
8 mC and 2.0 J
3
4 mC and 0.2 J
4
2 mC and 0.4 J