A parallel plate air capacitor is connected to a battery. If the plates of the capacitor are pulled farther apart, then state whether the following statements are true or false.
a. Strength of the electric field inside the capacitor remains unchanged, if the battery is disconnected before pulling the plates.
b. During the process, work is done by the external force applied to pull the plates irrespective of whether the battery is disconnected or not.
c. Strain energy in the capacitor decreases if the battery remains connected.
.