Three resistors 6 Ω, 6 Ω and 6 Ω are connected between the same two points, with two in parallel and the third in series with the parallel combination. The equivalent resistance is
A{'text': '4 Ω', 'label': 'A'}
B{'text': '18 Ω', 'label': 'B'}
C{'text': '12 Ω', 'label': 'C'}
D{'text': '9 Ω', 'label': 'D'}
Answer & Solution
Correct answer: D. {'text': '9 Ω', 'label': 'D'}
1. Parallel combination of two 6 Ω resistors: R_p = (6 × 6) / (6 + 6) = 3 Ω.
2. This parallel block is in series with the third 6 Ω resistor.
3. Series total: R = R_p + 6 = 3 + 6 = 9 Ω.
4. So equivalent resistance across the two ends is 9 Ω.
_Source: NCERT Class 12 Physics, Ch 3 "Current Electricity", §3 combinations_
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