Which of the following statement is TRUE?

• A. The equivalent resistance in series combination is equal to the largest resistance in the combination
• B. The equivalent resistance in series combination is smaller than the largest resistance in the combination
• C. The equivalent resistance in series combination is equal to the smallest resistance in the combination
• D. The equivalent resistance in series combination is larger than the largest resistance in the combination

Answer: (D)

Let us Suppose that the three Resistance R1, R2, R3 of 1 ohm, 2 ohms, and 3 ohms are connected in series respectively.
Now add all the resistance of the circuit we get
Req = R1 + R2 + R3Req = 1 + 2 + 3 = 5Ω
Now from the above result, we can conclude that the equivalent resistance in the series combination is larger than the largest resistance in the combination (since the largest resistance was 3Ω).
Therefore, Option.1. is correct.