RRB JE ECE (CBT II) Mock Test- 4 - Electronics and Communication Engineering (ECE) MCQ

FORTRAN and PASCAL both are procedural/imperative compiled third generation languages.

They allocate memory space for arrays during program compilation so the size of the array is fixed.

We have rms value given by,

V_rms=V_m√2

where, ​V_m is a peak value.

Thus, we have V_m=√2V_rms

Hence, V_m=√2×100=141.4V

• malloc() function is used to allocate a block of memory. A block of memory with a particular size is reserved and a pointer is returned which is of type void meaning that this function can be assigned to any type of pointers.
• calloc() function is used when there is a need for multiple blocks of storage, of same size, and then set all bytes to zero.
• realloc() function is used to move a reserved block of memory to another allocation of different dimensions. When the memory allocated by using calloc() or malloc() is insufficient or in excess, the size of the memory which has already been allocated can be changed using this function.

The given circuit is a summing amplifier,
The output voltage is given by

If R1 = R2 = R3 = 3 k Ω
V _out = -(1/3(V₁)) + 1/3(V₂) + 1/3(V₃))
V _out = - 1/3((V₁)) + (V₂) + (V₃))
Hence, the correct option is (B)

According to question,
Sum of root (α+β) = - b/a
So, (α + β) = - p ................ (i)
Product of root (αβ = c/a)
=> (αβ) = q ................... (ii)
From (i)
(α + β) = - p
=> (α + β)² = p²
=> α² + β² + 2αβ = p²
=> α² + β² = p² - 2q [αβ = q]
Hence α² + β² = p² - 2q
Hence, the correct option is (A)

• Colpitts oscillator consists of one inductor and two capacitor
• The Colpitts oscillator used CE configuration as shown in the figure 
• The capacitor with a centre tap is used in the feedback system of Colpitts oscillator
• It is used for generation of sinusoidal output signals with very high frequencies

   
Hence, the correct option is (A)

Only the following rights are available to foreign nationals:

Article 14 - Right to equality before law and equal protection of laws

Article 20 - Right to protection in respect of conviction for offences

Article 21- Right to protection of life and personal liberty

Article 21A - Right to elementary education

Article 22 - Right to protection against arrest and detention in certain cases

Article 23 - Prohibition of traffic in human beings and forced labour

Article 24 - Prohibition of employment of children in factories etc.,

Article 25 - Right to freedom of conscience and free profession, practice and propagation of religion

Article 26 - Right to freedom to manage religious affairs

Article 27 - Right to freedom from payment of taxes for promotion of any religion

Article 28 - Right to freedom from attending religious instruction or worship in certain educational institutions
Hence, the correct option is (C)

The gain of the inverting amplifier is given by
A_v = - R_f/R₁ = - R_f/2.2 = - 100
R _f = 220kΩ
Hence, the correct option is (D)

Modulation:

Modulation is a process of converting low-frequency signal (Audio frequency AF) with the High-frequency signal (Radio frequency RF) for better transmission and reducing the height of antenna (λ /4) required for transmission.

Demodulation:

Stack is used in situations where data have to be stored and then retrieved in reverse order. Stack follows LIFO, which means last in first out i.e the data which is stored last in the stack is retrieved first.
Real life implementation of stack is shown:

The ball which is stored last (D) will be the first one to be taken out of the container

The impedance at any point on a lossless transmission line is given by:

The maximum impedance is given by

Another expression for maximum impedance is
Z _max = V _max/I _max = Z ₀S

• In data communications, data elements are to be send; A data element is the smallest entity that can represent a piece of information: this is the bit
• In digital data communications, a signal element carries data elements; A signal element is the shortest unit (timewise) of a digital signal
• In other words, data elements are what sender needs to send; signal elements are what sender can send; therefore, data elements are being carried; signal elements are the carriers

Depletion in the concentration of ozone over a restricted area as spring time decline over Antarctica is called ozone hole. An ozone hole was discovered over Antarctica by Farman et al, 1985.

• Windows explorer has become a very powerful utility for navigation and searching directories for files of the system
• Windows Explorer is the file management tool that comes with Windows
• It gives the ability to rename, copy, move or delete the folders and files on the computer's drives
• Folders and files are displayed hierarchically within Windows Explorer
• Folders contain subfolders as well as files
• Windows Explorer is called File Explorer in Window 10

• For linear applications of op-amp, the op-amp should not be driven into saturation
• Negative feedback reduces the gain of the op-amp and prevents it from going into saturation
• Op-amp goes into saturation when operated in positive or no feedback

When the quantity of acids in the raining water is more than the average, then such rain is called 'Acid rain'.

We are aware that normally rainwater has a pH of 5.6.  When the pH of the rainwater drops below 5.6, it is called acid rain.

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by the wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition.

Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere. As mentioned earlier, burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides.

SO2 and NO2 after oxidation and reaction with water are major contributors to acid rain because polluted air usually contains particulate matter that catalyses the oxidation.

2SO2 (g) + O2 (g) + 2H2O (l) → 2H2SO4 (aq)

4NO2 (g) + O2 (g)+ 2H2O (l) → 4HNO3 (aq)

The bad effects of acid rain

• When acid rain falls and flows as groundwater to reach rivers, lakes etc, it affects plants and animal life in the aquatic ecosystem
• Acid rain is harmful to agriculture, trees and plants as it dissolves and washes away nutrients needed for their growth
• It causes respiratory ailments in human beings and animal
• It may also cause corrosion in many buildings bridges, monuments, fencing etc
• It causes irritation in the eyes and skin of human beings
• This rain reduces the lustre of the metals too
• Acid rain damages buildings and other structures made of stone or metal
• The Taj Mahal in India has been affected by acid rain

• Basic data type (Primitive Data Structure): Integer, Real, Boolean, Character; Primitive data types are also called simple data types since they cannot be further divided
• Non- primitive data structure is divided into linear data structure and non-linear data structure

1. Linear data structure: elements(data) form a sequence or a linear list.
Examples: Arrays, Linked List, Stacks and Queues
2. Non-Linear data structure: data are not arranged in sequence.
Example: Trees, Graphs

Leased Line:

A leased line is a connection that you rent for your exclusive use.

It offers a direct link from your premises to the data centre of your service provider. This is usually via a fibre optic connection.

Digital subscriber Line:

DSL is a communications medium used to transfer digital signals over standard telephone lines. Along with cable Internet.

DSL is one of the most popular ways ISPs provide broadband Internet access.

• A galvanometer can be converted into an ammeter by connecting a shunt resistance parallel to it
• A shunt is basically a wire of very small resistance
• A galvanometer can be converted into a voltmeter by connecting a very high resistance in the series
• A voltmeter is used to measure the potential difference whereas an ammeter is used to measure the electric current
• A galvanometer is used to measure small electric current in a circuit

A parallel combination of two 2 ohms resistance gives
R’ = 2 || 2 = 1 Ω

Connecting this combination in series with 2 Ω resistance gives
R_eq = R’+ 2 = 1 + 2 = 3
Hence, A parallel combination of two resistance (which will be 1 ohm) joined in series with the third resistance (2 ohm)

An operating system is a system software that acts as an interface between the user and the hardware resources. It provides a variety of services to the computer.

It performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

Some popular Operating Systems include Linux and Windows.

Windows Operating System

Every computer needs an operating system for operating a computer. There are few around and Microsoft Windows is just one of them. 
Some of the functions the Windows operating system allows to do are: 

• Access applications (programs) on the computer (word processing, games, spreadsheets, calculators and so on)
• Load any new programs on to the computer
• Manage hardware such as printers, scanners, mike, digital cameras
• Manage how files are stored on a computer (File Management, covered later in this module)
• Change computer settings such as colour schemes, screensavers, and the resolution of the monitor

There are several versions of Microsoft Windows in existence like Windows XP, Windows Vista, Windows 7 and Windows. 

Mohiniyattam and Kathakali dance are two classical dance forms associated with Kerala.

We know that

Approximate quantities of different gases in the atmosphere in PPM are given below.

• If the rate of rise of anode current (di/dt) is high results a non-uniform spreading of current over the junction
• Due to the high current density, this further leads to form local hot spots near the gate-cathode junction
• This effect may damage the SCR due to overheating. Hence, during turn ON process of SCR, the di/dt must be kept below the specified limits
• The di/dt capability of a thyristor increases when the gate current increase

Magnification of a lens is defined as the ratio of the height of the image to the height of the object.

m = h / [?]

h' = Height of the image

h = Height of the object

The figure shows the counter states on every clock states:
The mod 16 counter repeats after every 16 states.

Bus topology is a network setup in which each computer and network device are connected to a single cable or backbone. It is the easiest network topology for connecting computers or peripherals in a linear fashion and works well in a small network.

Concept:

From Law of conservation of mass in chemical reaction:

Total mass of reactants = Total mass of products.

Thus, the total mass of the substance remains same in a chemical change.

Physical Change :

• Physical changes are those where no new substances are formed.
• The molecules of the substance remain exactly the same before and after the change.
• Most physical changes are temporary and can be easily reversed to their previous form.
• Most physical changes are reversible.

Chemical Change:

• Chemical change occurs when there is a chemical reaction between the substances.
• Since new substances with different molecules are formed during chemical reactions, it is not easy to get back the original substances.
• Therefore, most chemical changes are permanent and irreversible.

1. Net primary productivity is the total organic matter stored by producers per unit area per unit time.
2. Gross primary productivity is the total organic matter synthesized by producers in the process of photosynthesis per unit area per unit time.
3. So, Net primary productivity = Gross productivity - Respiration and other losses.
4. Tropical rainforests occur over equatorial/subequatorial regions with abundant warmth and rainfall. Diversity and productivity are maximum as compared to other regions.