The question in 10:24 you said that the E field stays constant. However, as E=deltaV/delta r , given the potential difference (deltaV) is kept constant, doesn't the electric field strength have to vary with the distance between the plates? The question didn't really specify but I'm guessing nobody would assume that the battery voltage would just change
E= delta V/delta r is really a derivative. It applies to very (infinitessimally) small regions, but it is based on the idea that the Electric field between parallel plates is constant. We effectively consider two points in space that are so close together that the voltage and distance between points does not have enough space to change.
At 9:48, if those electric potential values (10V and 20V) were negative, then the electric field lines would be from left to right (because -10 > -20 and because electric field lines ALWAYS move from higher to lower potential). Is this assessment correct?
i do not really get why the magnitude of the electric field exprience by a charge between to plates (equipotential lines) is the same no matter what is the position of the charge
