Question

Need explanation step by step.
What will be the equivalent resistance between the point A and D?

Answer 1

1. The resistances directly connected to terminals C and D are useless - remove them.

2. The equivalent resistance of the box of resistances in the middle:

  (a) 10 ohms + 10 ohms = 20 ohms in each branch.

  (b) 20 ohms / 2 = 10 ohms is the effective resistance of the two branches combined (since they're parallel)

3. Effective total resistance = 10 ohms (A) + 10 ohms (box) + 10 ohms (D) = 30 ohms.

BTW, which booklet is that?

Answer 2

Correct answer is 30 ohm // let me know if i m wrong...

:)