I am making my way through the on-line textbook and I am presently at
http://www.allaboutcircuits.com/textbook/direct-current/chpt-2/circuit-wiring/
I get that 1, 2, and 3 are electrically equal, and the same with 4-5-6. I understand that the voltage between those two groups of points will be 10 volts. I think there is an error in the statement that 1&4 are the same as 2&3 (which are common). I would expect 2&3 to have no drop if the wire resistance is ignored.
http://www.allaboutcircuits.com/textbook/direct-current/chpt-2/circuit-wiring/
I get that 1, 2, and 3 are electrically equal, and the same with 4-5-6. I understand that the voltage between those two groups of points will be 10 volts. I think there is an error in the statement that 1&4 are the same as 2&3 (which are common). I would expect 2&3 to have no drop if the wire resistance is ignored.