BEE Fundamental Circuit Analysis 3 — Questions and Answers
Question 1: In the Norton equivalent circuit, the Norton current (I_N) is determined by:
- Open-circuiting the load terminals and measuring voltage
- Short-circuiting the load terminals and measuring current (Correct answer)
- Measuring current with load connected
- Dividing V_th by twice the load resistance
Correct answer: Short-circuiting the load terminals and measuring current
I_N is the short-circuit current at the terminals of the original network.
Question 2: A capacitor of 100 µF is charged to 12 V. How much energy is stored in it?
- 7.2 mJ (Correct answer)
- 1.2 mJ
- 600 µJ
- 14.4 mJ
Correct answer: 7.2 mJ
E = ½CV² = ½ × 100×10⁻⁶ × 144 = 7.2×10⁻³ J = 7.2 mJ.
Question 3: Which of the following correctly describes a node in circuit analysis?
- A closed path through the circuit
- A point where two or more circuit elements meet (Correct answer)
- A branch carrying one current
- An open-circuit terminal
Correct answer: A point where two or more circuit elements meet
A node is a junction point connecting two or more circuit elements, used to apply KCL.
Question 4: For maximum power transfer from a source with internal resistance R_s to a load R_L, the condition is:
- R_L = 0
- R_L = ∞
- R_L = R_s (Correct answer)
- R_L = 2R_s
Correct answer: R_L = R_s
Maximum power is delivered to the load when R_L equals the Thevenin resistance R_th (source resistance R_s).
Question 5: In mesh analysis, a mesh current is:
- The actual current in every element
- A hypothetical current circulating in a closed loop (Correct answer)
- The sum of all branch currents
- The Norton equivalent current
Correct answer: A hypothetical current circulating in a closed loop
Mesh currents are fictitious loop currents assigned to each independent mesh to set up KVL equations.
Question 6: An inductor of 50 mH carries a current of 4 A. What energy is stored in it?
- 100 mJ
- 400 mJ (Correct answer)
- 0.8 J
- 400 µJ
Correct answer: 400 mJ
E = ½LI² = ½ × 0.05 H × 16 A² = 0.4 J = 400 mJ.
Question 7: The voltage divider rule applies when two resistors R1 and R2 are connected in:
- Parallel across the source
- Series across the source (Correct answer)
- Delta configuration
- Star configuration
Correct answer: Series across the source
The voltage divider rule gives V_R1 = V_s × R1/(R1+R2) only when R1 and R2 are in series.
BEE Fundamental Circuit Analysis 3
In the Norton equivalent circuit, the Norton current (I_N) is determined by: