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Electrical Engineering QUESTION #2176
Question 1
In a superposition problem, a $5\,\Omega$ resistor carries $1\,\text{A}$ when only $V_1$ is active, and $-0.5\,\text{A}$ when only $I_1$ is active. The actual power dissipated in the resistor when both sources act simultaneously is:
  • $1.25\,\text{W}$✔️
  • $3.125\,\text{W}$
  • $6.25\,\text{W}$
  • $1.875\,\text{W}$
Correct Answer Explanation
Superposition applies to current (not power): $I_{total} = 1 + (-0.5) = 0.5\,\text{A}$. $P = I^2 R = (0.5)^2\times5 = 1.25\,\text{W}$. Directly superimposing powers would give $1^2\times5 + 0.25\times5 = 6.25\,\text{W}$ — a common but incorrect approach.