Question Detail
Question
Calculate the total resistance between the points A and B for the circuit shown (refer to the circuit diagram on page 4).
Correct Answer
Option C is the correct answer.
Detailed Explanation
The circuit consists of a 4 ohm resistor in series, followed by a parallel combination of a 1 ohm and 2 ohm resistor, and then a 3 ohm resistor in series. First, calculate the equivalent resistance of the parallel part: Rp = (R1 * R2) / (R1 + R2) = (1 ohm * 2 ohm) / (1 ohm + 2 ohm) = 2/3 ohm ≈ 0.6667 ohm.Next, add all series resistances: Rtotal = 4 ohm + Rp + 3 ohm = 4 ohm + 0.6667 ohm + 3 ohm = 7.6667 ohm. Rounding to two decimal places gives 7.67 ohm.
Hint
Combine parallel resistors first, then add all series resistors.