UPSC ESE Electronics & Telecom Solved Papers

Consider the following statements regarding impedance matching:

1. When the line is terminated in an impedance other than its characteristic impedance, reflection will occur and there will be standing waves of voltage and current along the line which may be very large if there is considerable mismatch.
2. The single-stub device has the advantage that it will match any load.
3. The double stub has the disadvantage that the line length needs to be adjustable.

Which of the above statements are correct?

The wave impedance in $z$ direction for TE wave is

Which one of the following is the ratio of power lost per unit length to the twice of power transmitted?

A section of X-band waveguide with dimensions $a=2.286\text{ cm}$ and $b=1.016\text{ cm}$ has perfectly conducting walls and is filled with a lossy dielectric ($\sigma_{d}=367.5\ \mu\text{S/m}$, $\epsilon_{r}=2.1$, $\mu_{r}=1$). The cutoff frequency of $\text{TE}_{10}$ for the dominant mode of propagation at a frequency of 9 GHz is

The antenna or array designed to yield directive gain appreciably greater than that obtainable from uniform distribution has become known as

In antennas, if $S_{A}$ is the input signal generated by the source (by the receiving antenna) at temperature $T_{A}$, $T_{E}$ is the effective noise temperature of the receiver network (referred to the input terminal), $B$ is bandwidth and $k$ is Boltzmann's constant, then the output signal-to-noise ratio is

The average value of the electrostatic field over the volume $V$ of a sphere due to a point charge $q$ somewhere within the sphere, where $r_{0}$ is the position of the charge, is

In the relation between the field and the potential, if $r < a$, then the potential at a point inside a uniformly charged sphere of radius $a$, is

Which one of the following techniques is used to speed up the multiplication of two signed binary numbers in 2's complement notation?

Which one of the following functions is not correct for an operating system?

Which of the following basic steps are needed in order to perform a memory read operation?

1. The address of the location from which the word is to be read is loaded into the memory address register (MAR).
2. A signal, called read (issued by the CPU indicating that the word whose address is in the MAR) is to be read into the MDR.
3. Corresponding to the memory delay in reading the specified word, the required word will be loaded by the memory into the MDR ready for use by the CPU.

Select the correct answer using the code given below.

Which one of the following addressing modes is used to compute the address of the operand by adding a constant value to the content of a register?

Which of the following statements is/are correct for memory-mapped I/O?

1. The advantage of memory-mapped I/O is the ability to execute a number of memory-dedicated instructions on the registers in the I/O devices in addition to the elimination of the need for dedicated I/O instructions.
2. The disadvantage of memory-mapped I/O is the need to dedicate part of the memory address space for I/O devices.

Select the correct answer using the code given below.

Which one of the following addressing modes is similar to the register indirect addressing mode in the sense that the effective address of the operand is the content of a register, which is included in the instruction?

A floating-point (FP) number is said to be normalized, if the leftmost bit of the mantissa is

In order to keep track of the instruction locations, which one of the following contains the value of memory location assigned to the instruction or operand being processed?

Addition of two $n$-bit numbers $A$ and $B$ can be carried out using $n$ consecutive full adders in an arrangement, which is known as

Which of the following instructions are long and allow maximum parallelism since each bit controls a single control line?

Which one of the following tables is generated in pass one and has an entry for every symbol in the program to perform its function?

Which one of the following is the entity that can combine object modules that may have resulted from assembling multiple assembly modules separately?

A unity feedback system has

$$G(s)=\frac{K(2s+1)}{s(4s+1)(s+1)^{2}}$$

What is the value of $K$ if the steady-state value of error is to be less than 0.1, when an input $r(t)=1+5t$ is applied?

For the given control system, what is the value of $K$ so that there is 10% error in the steady state?

In an underdamped second-order system, the time required for the waveform to go from 0.1 of the final value to 0.9 of the final value is called

The open-loop transfer function of a unity feedback system is given by

$$G(s)=\frac{K}{s(\tau s+1)}$$

By what factor should the amplifier gain $K$ be multiplied so that the damping ratio is increased from 0.25 to 0.75?

Consider the following statements regarding feedback compensation of control system:

1. A faster response can be achieved by the use of parallel compensation.
2. The environmental conditions in which the feedback control system is to be utilized affect the stability of the controlled quantity.
3. The degree of accuracy and the stability of a control system can be improved by the use of a cascade compensator.

Which of the above statements are correct?