Friday, 28 June 2019

TRB COMPUTER SCIENCE 2019 ANSWER KEY


1) Which of the following statement is true Cannot change operator templates
2) A node in a linked list consists of ______ and ______ Data, link
3) Floating point is always interpreted to represent a number in the following form m x re
4) Match the Following
1. Public sector - a. Banking
2.Private sector - b. Poultry
3. Primary sector - c. Profit motive
4. Tertiary sector - d. Service motive 

1 - b, 2 - c, 3 - a, 4 - d

5) Which of the following is/are correct DISTINCT keyword is used to remove duplicates
6) For a database relation R(a,b,c,d) where the domains of a, b, c, d include only atomic values, only the following functional dependencies and those that can be inferred from them hold.
a --->c
b --->d
This relation is
In First Normal Form but not in Second Normal For

7) Thrashing
Implies excessive page I/O activity
8) The unconditional branching instructions are JMP
9)

F=XOR (P,Q)

10)  Consider the following two statements
I. A publicly derived class is a sub class of its base class.
II. Inheritance provides code reuse.
Which of the following statement is correct

Both the statement I and II are correct

11)  Associative registers used to implement page tables are also called as 
Translation look-aside buffers

12) Zero has two representations in sign magnitude method

13) Which method quantizes the object space into a finite number of cells Grid

14) The simplified SOP (Sum of Product) form of the Boolean expression (P+Q'+R').(P+Q'+R).(P+Q+R') is     
 (P+Q'.R')

15) Speed of microprocessor depends on 
width of data bus

16) Node-to-Node delivery of the data unit is the responsibility of the Data link  layer

17)Throughput of a system is

Number of programs processed by it per unit time

18) The process of recording sound, stored in the form of thousands of individual measurements, each at a discrete point in time is called 
Sampling

19) Who remarked "The light has gone out of our lives and there is darkness everywhere"? Nehru

20) A Truth Table gives the output state for each possible input state combinations

21) The dual of the switching x + yz is  x(y+z)

22) any alignment specified specified at cell level override  '


23) The state of a 12 bit register is 100010010111. What is its content if it represents the three decimal digits in the excess-3 code and in BCD? 
564, 897

24) Bridge has filtering capability

25) The book 'Castes and Tribes of Southern India' was written by Edgar Thurston

26) A pure ALOHA network transmits 200 bit frames on a shared channel of 200 Kbps. What is the throughput if the system (all stations together) produces 1000 frames per second 
135 frames

27) The type of Ethernet destination address 47:20:1B:2E:08:EE is 
Multicast

28) Which of the following html tag uses absolute URL 
https://trbpgc.onlineregistrationform.org/TRBPGCIDOC/Images/WD_S1_Q1_B.JPG

29) The directive required in any C++ program that uses either cin or cout is iostream.h

30) Optimal algorithm uses the concept of Replacing a page that will not be used for longest period of time

31) Which of the following sorting method is stable 
Insertion sort
32) Functions defined outside the class can be accessed using 
Scope resolution operator
33) The casual users access the stored database by
Executing interactive query

34) Which of the following flip flops is free from race around problem Mater slave JK

35)
FIRST 20 SECOND

36) Which interfaces accept request written in some other language to understand them with database Natural language interface

37) TIFF stands for Tagged Interchange File Format

38) C++ provides inline functions to reduce function call overhead, mainly for Small functions
39)  Overlay is A single contiguous memory that is used in olden days for running large programs by swapping

40) Which of the following is false Pointers are typically initialized to the empty string

41) What helps the user to find interesting projections of multi-dimensional data  
Geometric projection visualization

42) Divide and conquer principle is adopted in quick sort

43) The individual's attention always remains on track and the activity proceeds systematically without any serious distraction, this is termed as  Sustained attention

44) The Excess-3 code has ______ invalid codes  6

45) If a data item is declared as a protected access specifier then it can be accessed By the base and derived classes

46) An AVL tree is identical to a binary search tree, except that for every node in the tree, the height of the left and right sub-trees can differ by at most 1

47) If all resources have only a single instance, then we can define a deadlock detection algorithm that uses a variant of the resource allocation graph called Directed acyclic graph
48)
Remainder of available viewing space

49)
     14
102) Dimensionality reduction is not applied for     Log linear models
105) Arrange the following in chronological order.
1) Battle of Kanwah
2) First battle of Panipat
3) Battle of Ghagra
4) Battle of Chanderi

2 1 4 3

51) Which of the following regarding basic ER and relational models is INCORRECT
In a row of relational table, an attribute can have more than one value

106) Accumulator is used for
 Arithmetic, logic, I/O and load/store operations
107) Fork system call is used for
  Creation of a new process

108) FLOW control refers to set of procedures used to restrict amount of data the sender can send before waiting for acknowledgement
109) Digital Signature cannot provide
Confidentiality
110) The main container for <tr><th><td>
            Table
111) The file format that uses a shorthand representation of musical notes and duration stored in numeric form is MIDI
112) Compaction is possible only if Relocation is dynamic and done at execution time
113) If all resources have only a single instance, then we can define a deadlock detection algorithm that uses a variant of the resource allocation graph called wait-for
114) If the language has the capability to produce new data types, it is called as extensible
115) The focus and blur events are also part of Window events
116) The web has a phenomenon known as ________, in which a website that was previously an unknown and unvisited, all of a sudden becomes the Center of the Known Universe Flash Crowds
117) Which one of the following disability is not mentioned in the National Trust (1999) Act Hearing Impairment
118) The maximum number of nodes possible in a binary tree of height 'h' is 2h-1
119) The cosine measure and the tanimato coefficient are used for applications involving Sparse numeric data vector
120) The bubbles in bubble memory pack are created with the help of Magnetic field
121) Consider a schema R (A,B,C,D) and functional dependencies A->B and C->D. Then the decomposition of R into R1(A,B) and R2(C,D) is dependency preserving but not lossless join
122) Determine the base of the numbers for the given operation to be correct.

54/4=13
à8
123) A family of graphic characters that usually includes many type sizes and styles is called typeface
124) The Preamble of the Indian Constitution adopted on 26th November, 1949 did not include the terms. 1. Socialist
2. Secular
3. Integrity
4. Republic

1, 2 and 3

123) Which of the following is immune to all present and future attacks, no matter how much computational power the intruder has one One Time Padding
124) Which one of the following terms is not a part of the acronym 'POSDCORB' widely used in the field of educational management and administration Supervision
125) It is a class of machine learning techniques that make use of both labelled and unlabelled examples where learning models are called Semi supervised learning
125) Adrenaline - Breathing rate
126) density, weight, volume
127) The function abort() in C++ is declared in the header file stdlib.h
128) The directive used to make variable declaration compulsory in ASP is option explicit
129) Which of the following is not correct for virtual function in C++  Virtual function can be static.     
130) The transformation of data from main memory to cache memory is referred to as Mapping

131) 'O' Blood group man gets married with 'AB' Blood group woman. What are the impossible blood group for their child. O' and 'AB' Blood group

132) A code scheme has a hamming distance dmin=4. This code guarantees the detection of errors up to 3 bit

133) Name the malware computer program that replicates itself in order to spread to other computers Worm
134) Compared to CISC processors,RISC processors contain
         More register and smaller instruction set
135)

O(N)

136) In JavaScript , what does NaN function do
Return true, if the argument is not a number

137) The keyword void is used to indicate that the function does not return anything
138) Which statement gets affected when i++ is changed to ++i ?   a=i+i++;

139) In Rorschach ink blot test when excessive reaction upon colour is expressed by the subject it represents the subject's  Spontaneity of emotional expression
140) Black box testing finds interface error

141) The Programme for International Students Assessment (PISA) is a triennial international survey which aims to evaluate education systems worldwide by testing the skills and knowledge, is a worldwide study by the  OECD
142) We have a Channel with a 1 MHz bandwidth. The SNR for this channel is 63. What are the appropriate bit rate and signal level C= 6 Mbps and L=4
143) Which of the following is used to make an Abstract class Making at least one member function as virtual function
144) The web standard allows programmers on many different computer platforms to dispersed format and display the information. These programs are called Browser
145) Which of the following is not an inherent application of stack Job scheduling

146) In general, the animation may appear jerky and slow if each frame is displayed for more than about  1/15 of a second
147) 10GBase – ER can run for distances of 40 km, making it suitable for wide area applications

148)


P-4, Q-1, R-2, S-3


149) Everyone of us have an inherent desire to get an opportunity to dominate others, it may vary in intensity but it is surely exhibited by all of us in one or other situation, this is the need for Self – assertion
150) The flags in the flag register does not get affected by Data transfer instructions


Tuesday, 13 December 2016



Computer - Input Devices



Following are few of the important input devices which are used in a computer:
  • Keyboard
  • Mouse
  • Joy Stick
  • Light pen
  • Track Ball
  • Scanner
  • Graphic Tablet
  • Microphone
  • Magnetic Ink Card Reader(MICR)
  • Optical Character Reader(OCR)
  • Bar Code Reader
  • Optical Mark Reader(OMR)

Keyboard

Keyboard is the most common and very popular input device which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.
Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet.
The keys on the keyboard are as follows:
Sr.NoKeysDescription
1Typing KeysThese keys include the letter keys (A-Z) and digit keys (0-9) which generally give same layout as that of typewriters.
2Numeric KeypadIt is used to enter numeric data or cursor movement. Generally, it consists of a set of 17 keys that are laid out in the same configuration used by most adding machines and calculators.
3Function KeysThe twelve function keys are present on the keyboard which are arranged in a row at the top of the keyboard. Each function key has unique meaning and is used for some specific purpose.
4Control keysThese keys provide cursor and screen control. It includes four directional arrow keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc).
5Special Purpose KeysKeyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen.
Keyboard

Mouse

Mouse is most popular pointing device. It is a very famous cursor-control device having a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.
Generally it has two buttons called left and right button and a wheel is present between the buttons. Mouse can be used to control the position of cursor on screen, but it cannot be used to enter text into the computer.

Advantages

  • Easy to use
  • Not very expensive
  • Moves the cursor faster than the arrow keys of keyboard.
Mouse

Joystick

Joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions.
The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing(CAD) and playing computer games.
Joystick

Light Pen

Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube. When the tip of a light pen is moved over the monitor screen and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU.
Light Pen

Track Ball

Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted and by moving fingers on ball, pointer can be moved. Since the whole device is not moved, a track ball requires less space than a mouse. A track ball comes in various shapes like a ball, a button and a square.
Track Ball

Scanner

Scanner is an input device which works more like a photocopy machine. It is used when some information is available on a paper and it is to be transferred to the hard disc of the computer for further manipulation. Scanner captures images from the source which are then converted into the digital form that can be stored on the disc. These images can be edited before they are printed.
Scanner

Digitizer

Digitizer is an input device which converts analog information into digital form. Digitizer can convert a signal from the television or camera into a series of numbers that could be stored in a computer. They can be used by the computer to create a picture of whatever the camera had been pointed at. Digitizer is also known as Tablet or Graphics Tablet because it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for doing fine works of drawing and image manipulation applications.
Graphic Tablet

Microphone

Microphone is an input device to input sound that is then stored in digital form. The microphone is used for various applications like adding sound to a multimedia presentation or for mixing music.
Microphone

Magnetic Ink Card Reader(MICR)

MICR input device is generally used in banks because of a large number of cheques to be processed every day. The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called Magnetic Ink Character Recognition (MICR). The main advantages of MICR is that it is fast and less error prone.
Magnetic Ink Card Reader(MICR)

Optical Character Reader(OCR)

OCR is an input device used to read a printed text. OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.
Optical Character Reader(OCR)

Bar Code Readers

Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labelling goods, numbering the books etc. It may be a hand held scanner or may be embedded in a stationary scanner. Bar Code Reader scans a bar code image, converts it into an alphanumeric value which is then fed to the computer to which bar code reader is connected.
Barcode Reader

Optical Mark Reader(OMR)

OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked. It is specially used for checking the answer sheets of examinations having multiple choice questions.
Optical Mark Reader(OMR)

Computer - CPU(Central Processing Unit)



CPU consists of the following features:
  • CPU is considered as the brain of the computer.
  • CPU performs all types of data processing operations.
  • It stores data, intermediate results and instructions(program).
  • It controls the operation of all parts of computer.
CPU
CPU itself has following three components.
  • Memory or Storage Unit
  • Control Unit
  • ALU(Arithmetic Logic Unit)
Computer Architectures

Memory or Storage Unit

This unit can store instructions, data and intermediate results. This unit supplies information to the other units of the computer when needed. It is also known as internal storage unit or main memory or primary storage or Random access memory(RAM).
Its size affects speed, power and capability. Primary memory and secondary memory are two types of memories in the computer. Functions of memory unit are:
  • It stores all the data and the instructions required for processing.
  • It stores intermediate results of processing.
  • It stores final results of processing before these results are released to an output device.
  • All inputs and outputs are transmitted through main memory.

Control Unit

This unit controls the operations of all parts of computer but does not carry out any actual data processing operations.
Functions of this unit are:
  • It is responsible for controlling the transfer of data and instructions among other units of a computer.
  • It manages and coordinates all the units of the computer.
  • It obtains the instructions from the memory, interprets them, and directs the operation of the computer.
  • It communicates with Input/Output devices for transfer of data or results from storage.
  • It does not process or store data.

ALU(Arithmetic Logic Unit)

This unit consists of two subsections namely
  • Arithmetic section
  • Logic Section

Arithmetic Section

Function of arithmetic section is to perform arithmetic operations like addition, subtraction, multiplication and division. All complex operations are done by making repetitive use of above operations.

Logic Section

Function of logic section is to perform logic operations such as comparing, selecting, matching and merging of data.