Thanks so much for all your help damon!

I think this is my last one:

h t t p ://img408.imageshack.us/my.php?image=circuit1al8.png

The reading of the ammeter is 2 A. The reading of the voltmeter is 33 V. Determine the unknown resistance and emf (picture linked above- remove spaces).

3 answers

emf sets top most node to emf V.

Nodal at top node:

(emf - V)/5 = 2A

=> emf = 43V

ohms law at top node:

(43V - 33V)/12 = Current right branch = 0.83A

Current in left branch = A + 0.83 = 2.83A

R = 33/2.83 = 11.66 Ohms

Although, this question is a little odd because there's no ground.
ty so much dan!
No problem ^^