BEE Electric Circuit Analysis 2 — Questions and Answers
Question 1: In a series RLC circuit at resonance, which statement is correct?
- Impedance is maximum
- Current is minimum
- Impedance equals R only (Correct answer)
- Capacitive reactance exceeds inductive reactance
Correct answer: Impedance equals R only
At resonance, XL = XC, so they cancel and total impedance equals R alone.
Question 2: Thevenin's theorem states that any linear circuit can be replaced by a:
- Current source in parallel with a resistance
- Voltage source in series with a resistance (Correct answer)
- Voltage source in parallel with a capacitance
- Current source in series with an inductance
Correct answer: Voltage source in series with a resistance
Thevenin's theorem reduces any linear network to an equivalent voltage source (Vth) in series with a resistance (Rth).
Question 3: A capacitor of 100 μF is charged to 50 V. What is the energy stored?
- 0.125 J (Correct answer)
- 0.25 J
- 2.5 J
- 5 J
Correct answer: 0.125 J
Energy = ½CV² = ½ × 100×10⁻⁶ × 50² = 0.125 J.
Question 4: Which method uses node voltages as the primary unknowns to analyze a circuit?
- Mesh analysis
- Norton's theorem
- Nodal analysis (Correct answer)
- Superposition theorem
Correct answer: Nodal analysis
Nodal analysis applies KCL at each node and solves for node voltages as the primary unknowns.
Question 5: In an RL circuit with DC supply, the time constant τ is:
- R/L
- L/R (Correct answer)
- RL
- 1/(RL)
Correct answer: L/R
The time constant of an RL circuit is τ = L/R, representing the time to reach ~63.2% of the final current.
Question 6: Two resistors R1 = 6 Ω and R2 = 12 Ω are connected in parallel. What is the equivalent resistance?
- 18 Ω
- 4 Ω (Correct answer)
- 9 Ω
- 2 Ω
Correct answer: 4 Ω
Req = (R1 × R2)/(R1 + R2) = (6 × 12)/(6 + 12) = 72/18 = 4 Ω.
Question 7: The superposition theorem is applicable only to circuits that are:
- Non-linear and bilateral
- Linear and bilateral (Correct answer)
- Non-linear and unilateral
- Any type of circuit
Correct answer: Linear and bilateral
Superposition applies exclusively to linear, bilateral circuits where responses to independent sources can be added individually.
BEE Electric Circuit Analysis 2
In a series RLC circuit at resonance, which statement is correct?