Question

What is the electric field strength inside the capacitor after insulating handles are used to pull the electrodes away from each other until they are 1.0 cm apart? The electrodes remain connected to the battery during this process.

Answer 1

This question apparently comes after an EARLIER one,
where you were told either the voltage across the same
capacitor or the total charge stored in it.  You can't answer
THIS one without that information.