Answer
a) Elements A and C are connected in parallel.
b) $V_a = -V_c$
c) $-8V$
d) $V_F -4V$
Work Step by Step
a) Recall, when elements are connected in parallel, electrons will never go through both but rather have the option of which element they go through. Using this, we find that elements $\fbox {A and C}$ are in parallel.
b) We use Kirchhoff's Voltage Law:
$V_a + V_c = 0 \\ V_a = -V_c$
c) Using the result from part b, we find:
$V_c = -V_a = -8V$
Thus, it follows: $V_b = \fbox{-8V}$
d) We use Kirchhoff's Voltage Law and the result from above:
$8-4 + V_F = 0 \\ V_F = \fbox{-4V}$
