UPSC ESE Electronics & Telecom Solved Papers

At what condition does the Fermi energy level ($E_{F}$) lie exactly between the band gap for intrinsic semiconductor?

In resistance levels, the AC or the dynamic resistance of a p-n junction diode is defined by

Consider the following statements regarding comparison of FET with BJT:

1. BJT is less noisy than FET.
2. FET is current-controlled device, whereas BJT is voltage-controlled device.
3. FETs are more temperature stable compared to BJTs.
4. FETs are simple to fabricate and occupy less area on the single chip.

Which of the above statements are correct?

Which one of the following is correct regarding stability factor with standard notations?

Which one of the following is a transfer characteristic of NMOS with standard notations?

Which one of the following statements is correct for n-channel or p-channel MOSFET?

Which one of the following statements is not correct for typical h-parameter values for a transistor?

Which one of the following technologies consumes less power?

Which one of the following requires additional process steps in their fabrication?

In monolithic integrated circuits, the concentration of acceptor atoms in the region between isolation islands will be

A circuit that amplifies the difference between two signals is called

The output of an LVDT is connected to a 5 V voltmeter through an amplifier whose amplification factor is 200. An output of 2 mV appears across the terminals of the LVDT when the core moves through a distance of 0.5 mm. The milli-voltmeter scale has 100 divisions and scale can read to $1/5$ of a division. The sensitivity and the resolution of the instrument are respectively

The coil of a recording ammeter is 65 mm long and 25 mm wide. The rated current of the coil is 10 mA. The flux density in the air gap is 0.0046 $\text{Wb/m}^{2}$. The damping constant is 0.008 N-m/$\text{rad-s}^{-1}$. The moment of inertia is $0.008\ \text{kg-m}^{2}$. The spring constant is 0.016 N-m/rad. The Coulomb friction is $0.2\times10^{-6}\ \text{N-m}$. The number of turns on the coil to produce a deflection of $100^{\circ}$ at rated current is approximately

Consider the following statements regarding data acquisition systems:

1. Digital data acquisition systems are used when wide frequency width is required.
2. Analog data acquisition systems are more complex than digital systems.
3. Digital data acquisition systems are used when the physical quantity being monitored has a narrow bandwidth.

Which of the above statements are not correct?

Wave analyzer is also known as

What is the displayed rise time (approximately) when a pulse waveform with a rise time of 21 ns is applied to an oscilloscope that has an upper cutoff frequency of 50 MHz?

An FM telemetry system uses a 370 Hz–430 Hz voltage-controlled oscillator to carry the fuel level of 3000 l tank, where 370 Hz represents an empty tank and 430 Hz represents full tank. What level does 408 Hz represent?

Four strain gauges are mounted on a simple flat tensile specimen arranged for complete temperature compensation and maximum sensitivity when connected in a four-arm bridge circuit. An $8\times10^{5}\ \Omega$ calibration resistor is shunted across one of the strain gauges. If the gauge resistances are each 188 $\Omega$ and the gauge factors are 1.22, then the effective strain is

A 0–200 V voltmeter has a guaranteed accuracy of 1 percent of full-scale reading. The voltage measured by this instrument is 150 V. The percentage limiting error is

A voltage has a true value of 1.55 V. An analog indicating instrument with a scale range of 0–2.5 V shows a voltage of 1.48 V. What is the relative error?

The measurement precision of an instrument defines the smallest change in measured quantity that can be observed, which is called

Consider the following statements:

1. The caesium beam and the hydrogen maser are the primary or absolute standards.
2. The rubidium vapour standard is based on the hyperfine transition in rubidium-78 gas, between the states $F=2$ and $F=1$.
3. The secondary standard of e.m.f. is the unsaturated Weston cell.

Which of the above statements are correct?

Which one of the following statements is correct regarding standards of measurements?

A path is a particular subgraph consisting of an ordered sequence of branches having which of the following properties?

1. At all but two of its nodes, called internal nodes, there are incident exactly two branches of the subgraph.
2. At each of the remaining two nodes, called terminal nodes, there is incident exactly one branch of the subgraph.

Select the correct answer using the code given below.

What is the value of the source current ($I_{s}$) of the given network in the figure?