Parallel network measurement — if an ideal voltmeter indicates 12 V across the source in a simple parallel circuit, what is the voltage across branch resistor R2?

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Solve this multiple-choice question and choose the correct option.

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Introduction / Context:In a parallel circuit all branches share the same two nodes, so the branch voltage equals the source (node-to-node) voltage. This property simplifies measurement and analysis. Given Data / Assumptions: Ideal voltmeter reads 12 V across the source terminals. R2 is connected in parallel across the same source nodes. Wiring and instruments are ideal (no wiring drop, no meter loading). Concept / Approach:By definition of parallel, the voltage across each branch element equals the node-to-node voltage supplied. Ohm’s law then determines each branch current independently from the common voltage and its resistance. Step-by-Step Solution: 1) Identify that R2 spans the same two nodes as the source.2) Therefore VR2 = VS by parallel definition.3) Given VS = 12 V, set VR2 = 12 V.4) Branch current can be computed separately: IR2 = 12 V / R2. Verification / Alternative check:Measure voltage across any other branch (e.g., R1). It will also read 12 V, confirming equal branch voltages in parallel. Why Other Options Are Wrong: VS − 12 V: nonsensical here because VS is 12 V.0 V: only if R2 were shorted out by nodes at the same potential, which contradicts parallel to source.More information / depends on R2: resistance value affects current, not the parallel branch voltage. Common Pitfalls:Transferring series “voltage division” intuition to parallel networks; misplacing meter leads to unintended nodes. Final Answer:12 V

Parallel network measurement — if an ideal voltmeter indicates 12 V across the source in a simple parallel circuit, what is the voltage across branch resistor R2?

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