The equivalent resistance between P and Q is: |
8 Ω 7.5 Ω 16 Ω 12 Ω |
8 Ω |
The correct answer is Option (1) → 8 Ω Given: We need to find the equivalent resistance between points $P$ and $Q$. From the circuit, observe that the $3\ \Omega$ resistor (vertical) and the $6\ \Omega$ resistor (left side) are connected between the same two points — both joining the top point $P$ to the central node. Hence, they are in parallel: $R_{PO} = \left( \frac{1}{3} + \frac{1}{6} \right)^{-1} = 2\ \Omega$ Now, the circuit reduces to a triangle between points $P$, $O$, and $Q$ with the following resistances:
The path through $O$ gives a total resistance of: $R_{POQ} = R_{PO} + R_{OQ} = 2 + 10 = 12\ \Omega$ This $12\ \Omega$ path is in parallel with the direct $24\ \Omega$ branch between $P$ and $Q$: $R_{PQ} = \left( \frac{1}{24} + \frac{1}{12} \right)^{-1}$ Calculate: $R_{PQ} = \frac{24 \times 12}{24 + 12} = \frac{288}{36} = 8\ \Omega$ Hence, the equivalent resistance between P and Q is: $R_{PQ} = 8\ \Omega$ |