In a cylindrical-rotor synchronous motor, if Ef= excitation emf and Vt= terminal voltage, then it is possible to have
1.Ef = Vt
2.Ef > Vt
3.Ef < Vt just like DC motor
4.Ef ahead of Vt
5.Ef behind Vt
From these, the correct answer is
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Solution
(i) Ef = Vt
(ii) Ef > Vt
(iii) Ef < Vt just like DC motor
(iv)Ef behind Vt
Two power stations A and B are located close together.Station A has 4 identical generators each rated as 100 MVA and having inertia constant of 9MJ/MVA. Station B has 3 alternators of identical rated as 300 MVA, 6 MJ/MVA. The equivalent inertia constant of the both machines on 150 MVA base is _________.
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Solution
The circuit shown below uses TTL gates. The current I is 1.6 mA when terminal B is left unconnected. When B is connected to A, the value of I
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Solution
I= 1.6 mA when terminal B is left unconnected.
Gate G1 will sink same current irrespective of terminal B.Hence, I will remains same.
For a short dipole, the distance in wavelengths where the inductive field are equal to the far field is
The power supplied to the circuit in figure, by the voltage and current sources respectively are
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Solution
A system is described by the following \(DEy(t)\frac{d^{2}y(t)}{dt^{2}}+3t\frac{dy(t)}{dt}+y(t)\) Then the system is
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Solution
Given V1= 5 sin (20 t + 10°) + 3 cos(30 t –20°) + 4 sin(40 t + 45°) and I1= 2 cos (20 t + 30°) – 4 sin (30 t + 60°)– 3 sin (40 t – 45°). The power transferred to network in watt is __________.
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Solution
In the circuit shown below,the switch is closed at t = 0,find VC2(∞).
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Solution
In the network shown below, find Rab.
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Solution
Read the following statements regarding the distance relays for protection of transmission line.
1.The reactance relay are least effected by power swings so that the relay are used for protection of long transmission line.
2.The reactance relay are least effected by ARC resistance, so that the relays are used as earth relays in transmission line.
3.Mho relays are acting as directional units for resistance relays in the zonal protection scheme.
Which of the above statements are correct?