What is the Norton resistance across terminals a and b for the circuit given below? [Figure description: A 3 A current source (arrow up) on the left in parallel with a 6 Ω resistor (current io flowing down through it). A dependent voltage source 9io (+ on left, - on right) in series with a 2 Ω resistor leads to terminal a; terminal b is on the bottom rail.]
- A. 1 ohm
- B. -1 ohm
- C. 3 ohm
- D. -3 ohm
Answer: B. -1 ohm
Explanation: Applying a test voltage source V at terminals a-b: with independent sources zeroed (3 A open), KCL and KVL yield Norton equivalent resistance Rth = -1 Ω.