Find the effective resistance in the diagram above

Answer Details

In the given diagram, resistors R1 and R2 are in parallel and their equivalent resistance can be calculated as follows:
1/Req = 1/R1 + 1/R2
1/Req = 1/6Ω + 1/6Ω = 2/6Ω
Req = 3Ω
Resistor R3 is in series with the combination of resistors R1 and R2. Thus, the total resistance of the circuit can be calculated as follows:
Rtotal = R3 + Req
Rtotal = 6Ω + 3Ω = 9Ω
Therefore, the effective resistance in the given diagram is 9Ω. Option (D) is correct.