(a) Calculate the capacitance of a capacitor whose parallel plates are 30 cm x 2.0 cm and are separated by 2.0 mm air gap. [1 cm² = 10-4 m²] 

(b) What is the charge on each plate if the capacitor is connected to a 20 V battery? 

(c) What is the electric field between the plates? 

(d) What will be the capacitance of the capacitor if the region between the plates is filled with the dielectric material whose dielectric constant K=80 (water)?