A parallel-plate capacitor in air has a plate separation of1.37 cm and a plate area of 25.0cm2. The plates are charged to a potential difference of268 V and disconnected from thesource. The capacitor is then immersed in distilled water. Assumethat distilled water is an insulator.
(a) What is the charge on the plates before immersion?
1 pC
What is the charge on the plates after immersion?
2 pC
(b) What is the capacitance after immersion?
3 pF
What is the potential difference after immersion?
4 V
(c) What is the change in energy of the capacitor?
ΔU = Uwater -Uair = 5nJ