Practice technical discipline questions for Electrical Machines, Power Systems, Power Electronics & Drives, Control Systems, Network Theory, and Switchgear with worked solutions.
Marking scheme: +1.00 positive, 0.00 negative (CIL CBT Pattern).
In a control system, a process is regulated by both positive and negative feedback loops. Consider a system where the output $y(t)$ is governed by the differential equation:
$$\frac{dy}{dt} = k_1 y(t) - k_2 y^2(t)$$where $k_1$ and $k_2$ are positive constants. Which of the following statements accurately describes the roles of positive and negative feedback in this system?
Which of the following factors most directly reduces the efficiency of a long transmission line?
What continuity correction is typically applied when using the normal approximation for the binomial distribution?
In an auto-sequential commutated inverter, incomplete discharge of the commutation capacitor results in
What is the function of the turbulator in a low oil circuit breaker?
Given two dielectric media with $\epsilon_1 > \epsilon_2$, and an electric displacement vector $D_1$ in medium 1 incident at an angle $\theta$ with respect to the normal of the boundary, what can be said about the magnitudes of $D_2$ and $E_2$ in medium 2?
In a series RLC circuit, the natural frequency (in rad/sec) is given by
For the equation $y'' - 4y' + 4y = 0$, what is the form of the general solution?
Why are MI instruments less accurate for AC measurement?
A solid is bounded by $x^2 + y^2 \le 4$, $0 \le z \le 3$. If the density at any point is $\delta(x, y, z) = z$, what is the mass of the solid?
An infinitely long line charge of density $\rho_l = 6\,\mu\text{C/m}$ is placed along the z-axis. Coaxial with it is a thin cylindrical shell of radius $a = 1\text{ m}$ carrying a uniform surface charge density $\rho_s = -(3/\pi)\,\mu\text{C/m}^2$. Using Gauss's law, determine the electric flux density $D$ as a function of radial distance $r$.
A system is stable if all closed-loop poles:
Which parameter can be varied using PWM to control inverter output?
Determine the Gray code of decimal number 43.
Which law forms the basis of mesh analysis?
In the transient analysis of an inductor, which of the following statements is correct regarding the behaviour of inductor current at the instant of switching?
Which component of Single-Phase Energy Meter (SPEM) controls the speed of the rotating disc?
A toroidal magnetic core of mean circumference 2TR and uniform cross-sectional area A is wound with N turns of a tightly coupled winding carrying current I. The core material is linear up to saturation, with relative permeability $\mu_r$ beyond which the flux density cannot exceed $B_{\text{sat}}$. Assume fringing and leakage flux are negligible, and that the magnetic field is uniformly distributed within the core.
Under these conditions, determine the critical value of current (i.e. the maximum permissible excitation current $I_{\text{max}}$) at which the flux density in the core just attains $B_{\text{sat}}$.
Which of the following is the effect on resonant peak if the damping ratio of a second order control system increases?
In potential transformer, the ratio error has importance in _____ while for _____ both ratio and phase angle errors are involved.
If three identical resistors of resistance R each are connected in a delta (Δ) configuration, what is the equivalent resistance of each branch when converted into a star (Y) configuration?
A chemical tank leaks fluid at a rate proportional to the amount present. If the initial quantity is 80 liters and after 1 hour only 60 liters remain, which linear first-order ODE correctly models this scenario?
What is the average value of a signal x(t) over interval [0,T]?
Which statement is true about the torque on a dipole in a uniform electric field?
What is the typical commutation frequency range of the smaller size and light weight four-quadrant transistor chopper?