Ronald Raygun wrote:
Well I used 2g 2way light switch.

Is there a prize?

There is no prize other than your own satisfaction, but if there were
a prize, you would be disqualified on grounds of being too expert. I
was interested in whether harry could do it. :-)

Presuming that the "g" in your "2g 2way" stands for "gang", i.e. that
the switch has two poles, each of which can be switched 2 ways, in
what is commonly referred to as a DPDT switch, then yes, that's the
answer to Q1. Indeed I have already given wiring solution for that
one.

A 2g 2way switch is two seperate SPDT switches with SPDT defined here

http://en.wikipedia.org/wiki/Switch

But Q2 explicitly specifies that you must use two switches, one to
operate each lamp.

I did a 2g means two switches on the same faceplate:-)

I find I need two DPDT switches for that (I don't
know if there is a simpler solution), and the puzzle lies in working
out how to wire them up so that when switch A is on and B is off,
then the two cores X and Y of the cable are connected to + and -,
respectively, whereas when switch B is on and A is off, you want X
and Y to be - and +, respectively, instead.

When you turn both switches on, you don't want to short out the
battery, or blow your fuse if there is one, as you would if your
solution were based on two 2g 1way (DPST) switches.

Turning both switches on simultaneously is an operator error
condition, since you can't turn both lamps on together. What gets
connected to X and Y in those circumstances may be undefined if you
wish, but preferably it should be that X and Y are both disconnected
from the battery, same as when both switches are off.

Ah, now you adding bits to make it harder. My setup does not disconnect the
lights from the battery.

--
Adam