Q. The total impedance of the secondary winding, leads, and burden of a 5 A CT is 0.01 Ω. If the fault current is 20 times the rated primary current of the CT, the VA output of the CT is Solution: Given that, impedance of secondary winding = 0.01 Ω Rated current = 5 A fault current = ...

Q. Five alternators each rated 5 MVA, 13.2 kV with 25% of reactance on its own base are connected in parallel to a busbar. The short-circuit level in MVA at the busbar is                  . Ans: 100 Solution: Reactance of each alternator = 0.25 As all the five alternators are connected in ...

Q. If 𝑓 = 2𝑥3 + 3𝑦2 + 4𝑧, the value of line integral ∫𝐶 grad𝑓 ∙ 𝑑𝐫 evaluated over contour C formed by the segments (-3, -3, 2)→(2, -3, 2) →(2, 6, 2) →(2, 6, -1) is Ans:

Q. A current controlled current source (CCCS) has an input impedance of 10 Ω and output impedance of 100 kΩ. When this CCCS is used in a negative feedback closed loop with a loop gain of 9, the closed loop output impedance is (A) 10 Ω (B) 100 Ω (C) 100 kΩ (D) 1000 kΩ Ans: 1000 kΩ ...

Q. Given, 𝑉𝑔𝑠 is the gate-source voltage, 𝑉𝑑𝑠 is the drain source voltage, and 𝑉𝑡ℎ is the threshold voltage of an enhancement type NMOS transistor, the conditions for transistor to be biased in saturation are (A) 𝑉𝑔𝑠 < 𝑉𝑡ℎ ; 𝑉𝑑𝑠 ≥ 𝑉𝑔𝑠 − 𝑉𝑡ℎ (B) 𝑉𝑔𝑠 > 𝑉𝑡ℎ ; 𝑉𝑑𝑠 ≥ 𝑉𝑔𝑠 − 𝑉𝑡ℎ (C) 𝑉𝑔𝑠 ...

Q. The characteristic equation of a linear time-invariant (LTI) system is given by ∆(𝑠) = 𝑠4 + 3𝑠3 + 3𝑠2 + 𝑠 + 𝑘 = 0. The system is BIBO stable if Ans: Option (C) Solution:

Q. A three-phase synchronous motor draws 200 A from the line at unity power factor at rated load. Considering the same line voltage and load, the line current at a power factor of 0.5 leading is (A) 100 A (B) 200 A (C) 300 A (D) 400 A Ans: 400 A

Q. The parameter of an equivalent circuit of a three-phase induction motor affected by reducing the rms value of the supply voltage at the rated frequency is (A) rotor resistance (B) rotor leakage reactance (C) magnetizing reactance (D) stator resistance Ans: magnetizing reactance ...

Q. A six-pulse thyristor bridge rectifier is connected to a balanced three-phase, 50 Hz AC source. Assuming that the DC output current of the rectifier is constant, the lowest harmonic component in the AC input current is (A) 100 Hz (B) 150 Hz (C) 250 Hz (D) 300 Hz Ans: 250 Hz ...

Q. A 5 kVA, 50 V/100 V, single-phase transformer has a secondary terminal voltage of 95 V when loaded. The regulation of the transformer is (A) 4.5% (B) 9% (C) 5% (D) 1% Ans: 5% Solution: Voltage regulation is the change in secondary terminal voltage from no load to full load ...

Q. The symbols, 𝑎 and 𝑇, represent positive quantities, and 𝑢(𝑡) is the unit step function. Which one of the following impulse responses is NOT the output of a causal linear time-invariant system? (A) 𝑒+𝑎𝑡𝑢(𝑡) (B) 𝑒−𝑎(𝑡+𝑇)𝑢(𝑡) (C) 1 + 𝑒−𝑎𝑡𝑢(𝑡) (D) 𝑒−𝑎(𝑡−𝑇)𝑢(𝑡) Ans: 1 + 𝑒−𝑎𝑡𝑢(𝑡) ...

Q. Consider five people – Mita, Ganga, Rekha, Lakshmi and Sana. Ganga is taller than both Rekha and Lakshmi. Lakshmi is taller than Sana. Mita is taller than Ganga. Which of the following conclusions are true? Lakshmi is taller than Rekha Rekha is shorter than Mita Rekha is taller ...