Q. Which one of the following statements is true about the digital circuit shown in the figure A. It can be used for dividing the input frequency by 3. B. It can be used for dividing the input frequency by 5. C. It can be used for dividing the input frequency by 7. D. It […]
Q. The number of roots of the polynomial, π 7 + π 6 + 7π 5 + 14π 4 + 31π 3 + 73π 2 + 25π + 200, in the open left half of the complex plane is (A) 3 (B) 4 (C) 5 (D) 6 Ans: 3
Q. The equivalent impedance Zeq for the infinite ladder circuit shown in the figure is (A) j12 Ω                   (B) βj12 Ω                 (C) j13 Ω                  (D) 13 Ξ© Ans: j12Ξ© Sol:
The equivalent impedance Zeq for the infinite ladder circuit shown in the figure is Read More Β»
Q. A DC voltage source is connected to a series L-C circuit by turning on the switch S at time t = 0 as shown in the figure. Assume i(0) =Β 0, v(0) =Β 0 . Which one of the following circular loci represents the plot of i(t) versus v(t) ? Ans: Option B
Q. The per-unit power output of a salient-pole generator which is connected to an infinite bus, is given by the expression, π = 1.4 sin πΏ + 0.15 sin 2πΏ, where πΏ is the load angle. Newton- Raphson method is used to calculate the value of πΏ for π = 0.8 pu. If the initial
Q. Consider the two bus power system network with given loads as shown in the figure. All the values shown in the figure are in per unit. The reactive power supplied by generator G1 and G2 are QG1 and QG2 respectively. The per unit values of QG1, QG2, and line reactive power loss (Qloss) respectively
Consider the two bus power system network with given loads as shown in the figure Read More Β»
Q. The positive, negative and zero sequence impedances of a three phase generator are π1, π2 and π0 respectively. For a line-to-line fault with fault impedance ππ, the fault current is πΌπ1 = ππΌπ, where πΌπ is the fault current with zero fault impedance. The relation between ππ and π is Ans: Option A Sol:
The positive, negative and zero sequence impedances of a three phase generator are Read More Β»
Q. A 0-1 Ampere moving iron ammeter has an internal resistance of 50 mΞ© and inductance of 0.1 mH. A shunt coil is connected to extend its range to 0-10 Ampere for all operating frequencies. The time constant in milliseconds and resistance in mΞ© of the shunt coil respectively are (A) 2, 5.55Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β (B) 2,
Q. A separately excited dc motor has an armature resistance π π = 0.05 Ξ©. The field excitation is kept constant. At an armature voltage of 100 V, the motor produces a torque of 500 Nm at zero speed. Neglecting all mechanical losses, the no-load speed of the motor (in radian/s) for an armature voltage of
A separately excited dc motor has an armature resistance π π = 0.05 Ξ© Read More Β»
Q. A 1000 Γ 1000 bus admittance matrix for an electric power system has 8000 non-zero elements. The minimum number of branches (transmission lines and transformers) in this system are (up to 2 decimal places). Ans: 3500 Sol:
