What is the effective resistance between the points A and D? A) 1.3 Ω B) 2.2 Ω C) 10 Ω D) 12 Ω

Answer:
D
Explanation:
The resistors are in series (lined up in a row). So the overall resistance is the sum:
R = 3.0 Ω + 4.0 Ω + 5.0 Ω
R = 12 Ω
Answer is D.