CIL Management Trainee Electrical Solved Papers

A protective relay is defined as an electrical device that is connected between the main circuit and the circuit breaker to:

In a certain region, the current density is given by

where $J_0 > 0$, $\alpha > 0$, and $\vec{r}$ is the position vector. The charge density is zero at $t = 0$. For $t > 0$, how does the charge density $\rho(\vec{r}, t)$ behave?

Choose the correct option for Static VAR Compensator.

Static VAR Compensator is used for:

1. Voltage control
2. Surge impedance compensation
3. Improving the overall power factor
4. Making the system unstable

MOSFETs are preferred over BJT in IC technology because MOSFETs

Calibration of single-phase energy meter ensures:

Consider a peak detector circuit in figure (Assume diode is ideal) fed by 50-Hz sinusoidal having peak value $V_p = 10\text{ V}$. Let the load resistance $R = 10\text{ k}\Omega$. Determine the value of capacitance C (assume time constant RC value much higher than time period of sinusoidal $V_i$) that will result in peak to peak ripple of $2\text{ V}$.

$V_i$ and $V_o$ denote input and output voltages respectively.

Which of the following correctly defines a double excited magnetic system?

Choose the correct statement for the construction of a potential transformer.

S1: In potential transformer, there are thermal problems caused by overloads.

S2: Oil filled bushings are usually used for oil filled potential transformer.

The Quasi-saturation region is commonly observed in which of the following devices?

How does the starting current of a three-phase squirrel-cage induction motor compare with its rated current when the motor is started using the direct-on-line (DOL) starting method?

A single-phase half-wave controlled rectifier with an RL load ($R = 10\,\Omega$, $L = 20\text{ mH}$) is supplied by a $120\text{ V}$, $50\text{ Hz}$ AC source. If the average output voltage $E_{dc}$ is 25% of the maximum possible average output voltage $E_{dc,\text{max}}$, then the value of $\cos\alpha$ is:

Suppose $z = x^3 y^2$, with $x$ and $y$ dependent on $s$. How do you express $\frac{dz}{ds}$ in terms of partial derivatives and chain rule?

Let the Bilateral Laplace Transform of a signal $f(t)$ be $F(s)$ with a Region of Convergence (ROC) $R_f : \sigma_1 < \text{Re}\{s\} < \sigma_2$. If $g(t) = f(-t)$, which of the following is the correct Laplace Transform, $G(s)$, and its corresponding ROC, $R_g$?

The total electric field at a point due to multiple discrete charges is found using the:

A parallel RLC circuit exhibits resonance at $f_0 = 1\text{ MHz}$. The half-power frequencies are found to be $f_1 = 0.98\text{ MHz}$ and $f_2 = 1.02\text{ MHz}$. What is the shape of the frequency response curve and what is the implication on circuit design?

In entered variable map, the size of K-map is reduced by

Define the unit ramp signal r(t).

The continuous time signal is given by $x(t) = e^{-2(-t)}u(-t)$. What is its Laplace transform $X(s)$ and its Region of Convergence (ROC)?

Which of the following is an advantage of implementing a digital controller compared to analog compensators in modern control system design?

_____ are designed to minimise magnetising current and reduce reluctance at the interleaved corners by assembling the lamination stacks with a slightly larger core cross-section than standard transformers.

In a binary weighted resistor DAC, what is the ratio of the resistance values for adjacent bits?

If $f(z) = z^2 + 3z$ and $C$ is the circle $|z| = 3$, which value does the integral $\oint_C \frac{f(z)}{z - 2} \, dz$ yield according to Cauchy's integral formula?

Flux in the core of a transformer remains the same from no-load to full-load; this is the reason why _____ in a transformer remain the same from no-load to full-load.

Which of the following statements is correct about signed number representations in digital systems?

A) In sign-magnitude representation, the MSB represents the sign, and the remaining bits represent the magnitude.

B) In 1's complement representation, a negative number is obtained by flipping all the bits of its positive counterpart.

C) In 2's complement representation, a negative number is obtained by taking the 1's complement of its positive counterpart and adding 1.

Zero sequence reactance of the transformer does not depend on