UPSC ESE Electronics & Telecom Solved Papers

The highest frequency that is returned to the earth at a given distance is called

The mean sun does move at a uniform speed but otherwise requires the same time as the real sun to complete one orbit of the earth, this time being

Which one of the following statements is not correct regarding SONET networks?

A digital optical fiber communication system operating at a wavelength of $1\ \mu\text{m}$ requires a maximum bit error rate of $10^{-9}$. What is the theoretical quantum limit at the receiver in terms of the quantum efficiency of the detector and the energy of an incident photon?

With frequency reuse, several cells with no space in a given coverage area use the same set of frequencies. Two cells using the same set of frequencies are called

The component in the satellite that takes an uplink signal and converts into a downlink signal is called

An advantage of passive satellites is that they do not require sophisticated electronic equipment on board, although they are not necessary void of power. Some passive satellites require which one of the following for tracking and ranging purposes?

Some of the diffracted light continues down the fiber and some of it escapes through the cladding. The light rays that escape represent a loss in light power which is called

Numerical aperture is closely related to acceptance angle and is the figure of merit commonly used to measure

Consider the following statements regarding programmable interrupt controller 8259A:

1. 8259A is specifically designed for use with the interrupt signals (INTR/INT) of 8085 microprocessor.
2. It can solve eight levels of interrupt priorities in a variety of modes.
3. With additional 8259A devices, the priority scheme can be expanded to 32 levels.

Which of the above statements is/are not correct?

Consider the following statements regarding 8085 instruction set:

1. After execution of DAD instruction, if the result is larger than 16 bits, CY flag is set.
2. After execution of DCR instruction, S and CY flags will not be modified.
3. After execution of CMC instruction, only CY flag will be changed.

Which of the above statements is/are not correct?

If the memory chip size is $1024\times 1$ then the number of memory chips needed to design 8 Kbyte memory is

Which one of the following statements is correct for the given system?

$$y(n)=x^{2}(n)+\frac{1}{x^{2}(n-1)}$$

If the impulse response $h(n)$ and the output $y(n)$ of a system are given as $h(n)=\{2, 1, 0\text{ (zero)}, -1, 3\}$ and $y(n)=\{2, -5, 1, 1, 6, -11, 6\}$ then the input $x(n)$ of the system is

The approximate transition width of main lobe in Blackman window is

Consider the following statements regarding filters:

1. Cauer filter has equiripple passband and stopband.
2. For a given filter order, passband and stopband deviations, Cauer filters have more transition bandwidth as compared to Chebyshev filters.
3. Linear phase characteristics cannot be achieved in IIR filters.

Which of the above statements are correct?

Consider the following statements regarding 8051 microcontroller:

1. The size of RAM in 8051 is 128 bytes.
2. RAM locations 00–1FH are assigned to the register banks and stack.
3. RAM locations 20–2FH are available as a place to save byte-sized data.

Which of the above statements are correct?

Consider the following statements regarding nonvolatile RAM (NV-RAM) in 8051:

1. When the power is turned off, the contents are lost.
2. NV-RAM uses extremely power-efficient SRAM cells built out of CMOS.
3. It uses an intelligent control circuitry.

Which of the above statements are correct?

Which one of the following statements is not correct for CMOS technology in comparison with bipolar technology?

Consider the following statements regarding MOS circuit design process:

1. MOS circuits are formed on four basic layers: n-diffusion, p-diffusion, polysilicon and metal, which are isolated from one another by thick or thin silicon dioxide insulating layers.
2. Thin oxide (thinox) mask region includes n-diffusion, p-diffusion and transistor channels.
3. Polysilicon and thinox regions interact so that a transistor is formed where they cross one another.

Which of the above statements are correct?

The ratio of total number of transistors on the chip to the number of transistor circuits that must be designed in detail is known as

If $V$ is a scalar, then the given equation (in spherical coordinate system)

$$\frac{1}{r^{2}}\frac{\partial}{\partial r}\left(r^{2}\frac{\partial V}{\partial r}\right)+\frac{1}{r^{2}\sin\theta}\frac{\partial}{\partial\theta}\left(\sin\theta\frac{\partial V}{\partial\theta}\right)+\frac{1}{r^{2}\sin^{2}\theta}\frac{\partial^{2}V}{\partial\phi^{2}}=-\frac{\rho}{\epsilon}$$

is referred to as

The intrinsic impedance of free space is

Which one of the following is an angle at which there is no reflected wave when the incident wave is parallel (or vertically) polarized?

The condition for the low-loss transmission line is