2010 physics e1 Question 3-4 electricity- How do You solve it?

[MissIraq]

hiya
I'm confused with this question...

http://www.vcaa.vic.edu.au/vcaa/vce/studies/physics/pastexams/2010/2010physics1-w.pdf

for example to answer question 3, it wants me to say what the voltage is for light globe A and B.. so how do I get them?

Also,questions 6-8 , i dont really know how to solve them too. Like for example the lux resistance one, I dont get why the answer is doubled.. etc.

please help.

[schnappy]

Since they're in parallel V_drop across A and B is the same. Find the equivalent resistance of the two parallel components... it is 1 ohm.

Simplify it to a series circuit, of .5 ohm + (1 ohm of both lights) + .5 ohm, which is essentiall two 1 ohm resistances.

Equal resistances, so the voltage is half of the supply... 12V across the lights A and B.