Two resistors R1=4Ω and R2=6Ω are first connected in parallel across a 12V battery for 30min and are then re-connected in series across the same battery for the next 30min. Neglecting any change in resistance, what is the total electrical energy dissipated during the entire one-hour period?
a) 2.16×105J
b) 1.08×105J
c) 1.34×105J
d) 2.68×105J