Question

Find the equivalent resistance.

Answer 1

Answer:

18 Ω

Explanation:

As K and F are at the same voltage, we can redraw the diagram as in figure 2

Series resistances add directly, so we get figure 3

Adding parallel resistances gets us to figure 4

Now we can move two 6Ω resistances for clarification in figure 5

As the voltage between C and J will be identically split between D and H, there will be no voltage drop across the middle 6Ω resister and no current through it, identical to an infinite resistance, so that 6Ω can be eliminated as in figure 6

Add series resistances to get to figure 7

Add parallel resistances to get to figure 8

Add series resistances to get to figure 9

Answer 2

Answer:

Explanation:

Note the connection between D-L-H shorts out the resistors on the right. Those 4 resistors can be ignored.

The connection between D-L-K means the 2 resistors between C-D and C-K are in parallel. The equivalent resistance of 2 6-ohm resistors in parallel is 3 ohms.

Similarly the connection between K-L-H means the 2 resistors between J-K and J-H are in parallel. The equivalent resistance of 2 6-ohm resistors in parallel is 3 ohms.

Adding the resistors in series together:

A-C-L-J-D = 6 + 3 + 3 + 6

= 18 ohms