UPSC ESE Electronics & Telecom Solved Papers

Consider the speed control system shown in the figure wherein the inner loop corresponds to motor back e.m.f., the controller is an integrator with gain $K$ observes that the load is inertia only. What is the value of $K$ for which steady-state error to unit ramp input is less than $0.01\text{ rad/sec}$? ($V_{r}(s)=\frac{1}{s^{2}}$)

The subsystem that generates the input to the plant or process is known as

Consider the following statements regarding compensator:

1. The lead compensator reduces the noise signal level relative to the control signal.
2. Introduction of cascade lead compensator increases the gain crossover frequency and, consequently, the speed of the response of resulting system.
3. The lead compensation increases the system bandwidth.

Which of the above statements are correct?

Which of the following is/are used, when the cascade compensator does not employ pure integration?

Consider the following statements regarding signals:

1. Deterministic signal is a signal about which there is no uncertainty with respect to its value at any time.
2. Each signal within the ensemble has a certain probability of occurrence and the ensemble of signals is referred to as a random process.
3. EEG signal is an example of random signal.

Which of the above statements are correct?

Which one of the following techniques can be used to analyze and design the effect of loop gain upon the system's transient response and stability?

Consider the following statements regarding time response specifications:

1. Delay time is the time required for the response to reach 10% to 90% or 5% to 95% or 0% to 100% of its final value.
2. Peak time is the time required for the response to reach the first peak overshoot.
3. Settling time is the time required for the response to reach and maintain beyond a specified tolerance band, i.e., either 3% or 5% of the initial value.

Which of the above statements are not correct?

Which one of the following fibers has the distinct advantage of low intermodal dispersion?

Which one of the following statements is not correct?

The RF carrier range and IF bandwidth corresponding to AM radio receiver are respectively

For the same average transmitted or modulated signal power and the same average noise power in the message bandwidth, a coherent SSB receiver will have exactly the same output signal-to-noise ratio as

Over a certain binary communication channel, the symbol 0 is transmitted with probability 0.4 and 1 is transmitted with probability 0.6. It is given that $p(\epsilon/0)=10^{-6}$ and $p(\epsilon/1)=10^{-4}$, where $p(\epsilon/x_{i})$ is the probability of detecting the error given that $x_{i}$ is transmitted. What is the error probability of the channel?

Which one of the following noises arises in electronic devices such as diodes and transistors because of the discrete nature of current flow?

Which one of the following represents the output signal-to-noise ratio of a uniform quantizer? (where $P$ denotes average power of the message signal $m(t)$ and $R$ denotes number of bits per sample)

Removing the redundant information before encoding is the basic idea behind

Identify the given circuit shown in the figure.

In which one of the following techniques, RF binary signals are transmitted as given?

$$0 : \sqrt{2}p'(t)\cos\left[\omega_c - \left(\frac{\Delta\omega}{2}\right)\right]t$$

$$1 : \sqrt{2}p'(t)\cos\left[\omega_c + \left(\frac{\Delta\omega}{2}\right)\right]t$$

Which one of the following statements is not correct regarding the features of CDMA?

How many 6 MHz wide TV channels can be multiplexed on 800 MHz coaxial cable?

Statement (I): The magnetization curve is the relationship between air gap flux and the field winding m.m.f. or field winding current.

Statement (II): No-load magnetization curve is the graph between armature-generated e.m.f. and field current with constant armature speed.

Statement (I): Some of the common and familiar polymers are polyethylene (PE), nylon, polyvinyl chloride (PVC), polycarbonate (PC), polystyrene (PS) and silicone rubber.

Statement (II): Polymers include the familiar plastic and rubber materials.

Statement (I): Voltage (or potential difference) is the energy required to move a unit charge through an element.

Statement (II): Power is the time rate of expending or absorbing energy.

Statement (I): A transfer function is a function which relates the current or voltage at one port to the current or voltage at another port.

Statement (II): If the function has one or more poles in the right-half plane, then the function is non-minimum phase.

Statement (I): Antenna is a transformation device converting electromagnetic photons into circuit currents.

Statement (II): An antenna converts photons to currents or vice versa.

Statement (I): Shannon has shown that it is possible to achieve error-free communication by adding sufficient redundancy.

Statement (II): The addition of an extra check digit increases redundancy.