Difficulty: Easy
Correct Answer: 16 watts
Explanation:
Introduction / Context:
Power bookkeeping is essential for thermal design and source sizing. In any circuit, the total power delivered by the source equals the sum of the powers dissipated in all elements (ignoring storage in ideal reactive components at steady state).
Given Data / Assumptions:
Concept / Approach:
Conservation of energy requires that the source supplies the sum of branch powers. In parallel circuits, voltage across each branch is common, but power still adds linearly: P_total = Σ P_branch.
Step-by-Step Solution:
Write: P_total = P1 + P2.Substitute: P_total = 6 + 10.Compute: P_total = 16 W.
Verification / Alternative check:
If branch currents are I1 and I2 at common voltage V, then P_total = V * (I1 + I2) = V * I_total = V * I1 + V * I2 = P1 + P2, confirming additivity.
Why Other Options Are Wrong:
Common Pitfalls:
Mixing current-division or resistance calculations with power addition; power does not divide inversely like resistance.
Final Answer:
16 watts
Discussion & Comments