MS Master of Electrical Engineering 1 — Questions and Answers
Question 1: Which theorem states that the current through a resistor in a linear circuit equals the sum of currents from each independent source acting alone?
- Superposition Theorem (Correct answer)
- Thevenin's Theorem
- Norton's Theorem
- Maximum Power Transfer Theorem
Correct answer: Superposition Theorem
The Superposition Theorem states that in a linear circuit, the response is the sum of responses due to each independent source acting alone.
Question 2: What is the Nyquist sampling rate for a signal with a maximum frequency of 5 kHz?
- 10 kHz (Correct answer)
- 5 kHz
- 2.5 kHz
- 20 kHz
Correct answer: 10 kHz
The Nyquist sampling rate must be at least twice the maximum signal frequency, so 2 × 5 kHz = 10 kHz.
Question 3: In a three-phase power system, what is the relationship between line voltage (V_L) and phase voltage (V_ph) in a balanced star (Y) connection?
- V_L = √3 × V_ph (Correct answer)
- V_L = V_ph
- V_L = 3 × V_ph
- V_L = V_ph / √3
Correct answer: V_L = √3 × V_ph
In a balanced star connection, the line voltage is √3 times the phase voltage due to the 120° phase displacement between phases.
Question 4: Which type of semiconductor device is primarily used as a voltage-controlled current source in amplifier circuits?
- MOSFET (Correct answer)
- Diode
- Zener Diode
- Schottky Diode
Correct answer: MOSFET
A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) acts as a voltage-controlled current source where gate voltage controls drain current.
Question 5: What does the transfer function H(s) = 1/(s+a) represent in control systems?
- A first-order low-pass filter (Correct answer)
- A second-order system
- A differentiator
- A bandpass filter
Correct answer: A first-order low-pass filter
H(s) = 1/(s+a) represents a first-order low-pass filter with a single real pole at s = -a in the s-domain.
Question 6: In digital logic, what is the output of an XOR gate when both inputs are the same value?
- 0 (Correct answer)
- 1
- Undefined
- Depends on input voltage
Correct answer: 0
An XOR gate outputs 0 when both inputs are identical (both 0 or both 1) because it detects inequality.
MS Master of Electrical Engineering 1
Which theorem states that the current through a resistor in a linear circuit equals the sum of currents from each independent source acting alone?