List of practice Questions

A dc ammeter has a multiplication factor of 8 and its shunt current is 17.5 A, then the current through ammeter is:
A 200 V, 50 Hz, 1-phase energy meter makes 960 revolutions to supply a load of 0.8 pf for 2 hrs. If motor constant is 160 rev/kWh, then load current is:
If \( I_p, I_m, I_s \) are magnetising, primary and secondary currents of current transformer, then approximate phase angle \( \theta \) in degrees between \( I_p \) and reversed \( I_s \) is:
Choose the correct combination of the following: (a) At break-away point the root locus breaks from real axis into complex plane
(b) At break-away point the root locus breaks from imaginary axis into complex plane
(c) At break-in point the root locus enters the real axis from the complex plane
(d) At break-in point the root locus enters the imaginary axis from the complex plane

The transfer function of the following system is

Find the frequency of sustained oscillations for the following system when \( K = 48 \): \[ G(s)H(s) = \frac{K}{s(s^2 + 7s + 4)} \]
Find gain of the following open loop system having phase cross-over frequency of 1.732 rad/sec. \[ G(s)H(s) = \frac{1}{s(1+s)} \]
A state-space system is given by \[ \dot{x} = \begin{bmatrix}1 & -2 \\ 3 & -4\end{bmatrix}x + \begin{bmatrix}1 \\ 0\end{bmatrix}u, \quad y = \begin{bmatrix}1 & 2\end{bmatrix}x \] The controllability matrix [CM] is

The transfer function of the following signal flow graph is \( \frac{x_3(s)}{x_1(s)} \):

The transfer function of an RLC series circuit when input voltage is fed to \( R, L \) and output voltage is across \( C \) is:
If \( R(s) \) is input signal, \( C(s) \) is output signal and \( G(s)H(s) \) is feedback signal, then the steady-state error is given by
If the phase angle at gain cross-over frequency of a system is -116°, then the phase margin will be
For the given transfer function \( G(s) = \frac{5(s+4)}{(1+4s)(1+0.25s)} \), for large values of \( \omega \), the slope of the transfer function on the Bode plot is
A unity feedback system has open loop transfer function \( \frac{1}{(s^2 + 5)} \), then the closed loop transfer function is
The value of \( k \), where root locus cuts the jω axis in plotting root locus, is calculated by
A system has the following characteristic polynomial equation and it has three sign changes in the first column of Routh array. Choose correct choice for the number of roots on right and left side of s-plane. \[ s^4 + 3s^3 + 10s^2 + 5s + 10 = 0 \]
The line trap unit employed in carrier current relaying offers
The order of the lightning discharge current is
Consider the following statements:
1. By using bundled conductors in an overhead line, the corona loss is reduced
2. By using bundled conductors, the inductance of transmission line increases and capacitance reduces
3. Corona loss causes interference in adjoining communication lines
Which of these statements are correct?
The maximum reactive power generation of a generator is limited because of
A stranded conductor is expressed as 19/1 where the first number corresponds to ........ and the second number corresponds to ........
For open loop system, the sensitivity of overall transfer function for a small change in forward path transfer function \( G(s) \) is
In case of a transmission line, the corona ______
In case of overhead lines, normally ______ insulators are used at road crossings
In case of voltage control of a power system network, for the same voltage both the reactive power capacity of a shunt capacitor is _____ that of a series capacitor.