NieLit STA 2016 March 2016

 Question 1
Which of the following has lowest propagation delay?
 A ECL B TTL C PMOS D CMOS
Computer-Networks        Ethernet
Question 1 Explanation:
● Propagation Delay: It represents the transition time which elapses when the input level changes. The delay which occurs for the output to make its transition is the propagation delay.
● Characteristics of TTL logic:
○ Power dissipation is usually 10 mW per gate.
○ Propagation delays are 10 ns when driving a 15 pF/400 ohm load.
○ Voltage levels range from 0 to Vcc where Vcc is typically 4.75V - 5.25V. Voltage range 0V - 0.8V creates logic level 0. Voltage range 2V - Vcc creates logic level 1.
● Characteristics of Emitter Coupled Logic (ECL)
● The storage time is eliminated as the transistors are used in difference amplifier mode and are never driven into saturation.
● It is the fastest logic family and has the lowest propagation delay.
 Question 2
The number of address lines in a memory chip of size 8192*8 is
 A 8 B 12 C 13 D 16
Computer-Organization       Memory-Interfacing
Question 2 Explanation:
At every point in time, each address line can be one of two states (high or low). Some basic counting shows that N address lines can address 2​ n​ memory locations.
This problem can be solved using an equation
2​ n​ = x; where n is the number of address lines and x is the memory space
2​ n​ = 8192 = 2​ 13 n = 13
Total number of address line required is 13.
 Question 3
Vestigial sideband most commonly used in radio transmission
 A radio transmission B telephony C television transmission D all of the above
Question 3 Explanation:
Limitation of single-sideband modulation being used for voice signals and not available for video/TV signals leads to the usage of vestigial sideband. A vestigial sideband (in radio communication) is a sideband that has been only partly cut off or suppressed. Television broadcasts (in analog video formats) use this method if the video is transmitted in AM, due to the large bandwidth used. It may also be used in digital transmission, such as the ATSC standardized 8VSB.
Vestigial sideband (VSB) is a type of amplitude modulation ( AM ) technique (sometimes called VSB-AM ) that encodes data by varying the amplitude of a single carrier frequency . Portions of one of the redundant sidebands are removed to form a vestigial sideband signal - so-called because a vestige of the sideband remains.
 Question 4
The number of independent loops for a network with n nodes and b branch is
 A n-1 B b-n C b-n+1 D independent of "the number of nodes
Engineering-Mathematics       Graph-Theory
Question 4 Explanation:
● A loop is a closed path in a circuit. Loop counts starting at a node passing through a set of nodes and returning to the starting node without passing through any node more than once.
● A loop is said to be independent if it contains at least one branch which is not a part of any other independent loop.
● A network with ‘b’ branches, ‘n’ nodes and ‘L’ independent loops will satisfy the fundamental theorem of network topology.
b=L+n−1
L=b−n+1
 Question 5
Regular sets are closed under
 A Union B Concatenation C Kleene's closure D All of these
Theory-of-Computation       Regular-Language
Question 5 Explanation:
Regular sets are closed under union, concatenation and Kleene closure
 Question 6
Software that measures, monitors, analyzes and controls real world events is called
 A System Software B Real time software C Scientific Software D Business Software
Operating-Systems       Software-Types
Question 6 Explanation:
● System software is a type of computer program that is designed to run a computer’s hardware and application programs.
● Real-time software enables the user to execute various task and activities all at the same time, as long as the programs are kept open.Real-time software refers to programs that can perform their assigned duties and functions right when they are assigned to run their given processes, not after the program has been executed, and not on a scheduled date
● Scientific software is defined by three characteristics: (1) it is developed to answer a scientific question; (2) it relies on the close involvement of an expert in its scientific domain; and (3) it provides data to be examined by the person who will answer that question.
● Business software or a business application is any software or set of computer programs used by business users to perform various business functions. These business applications are used to increase productivity, to measure productivity and to perform other business functions accurately.
 Question 7
Dividing a project into segments and smaller units in order to simplify analysis,design and programming efforts is called
 A Modular approach B Top down approach C Bottom up approach D Left right approach
Software-Engineering       Basics
Question 7 Explanation:
● Dividing a project into segments and smaller units in order to simplify analysis,design and programming efforts is called Modular approach
● Modular design or “modularity in design”, is a design approach that subdivides a system into smaller parts called modules or skids that can be independently created and then used in different systems.
 Question 8
When a computer is first turned on or restart, a special type of absolute loader is executed called
Operating-Systems       File system-I/O-protection
Question 8 Explanation:
● A boot loader is a type of program that loads and starts the boot time tasks and processes of an operating system or the computer system. It enables loading the operating system with in the computer memory when a computer is started or booted up.
● A boot loader is also known as a boot manager or bootstrap loader. Bootstrap loader is a program that resides in the computer's EPROM, ROM, or other non-volatile memory. The bootstrap loader reads the hard drives boot sector to continue the process of loading the computer's operating system. The term bootstrap comes from the old phrase "Pull yourself up by your bootstraps."
 Question 9
The data manipulation language(DML)
 A refers to data using physical addresses B cannot interface with high-level programming language C is used to define the physical characteristics of each record D none of these
Database-Management-System       SQL
Question 9 Explanation:
● A data manipulation language (DML) is a computer programming language used for adding (inserting), deleting, and modifying (updating) data in a database.
● A DML is often a sublanguage of a broader database language such as SQL, with the DML comprising some of the operators in the language.
● Read-only selecting of data is sometimes distinguished as being part of a separate data query language (DQL), but it is closely related and sometimes also considered a component of a DML. some operators may perform both selecting (reading) and writing.
● A popular data manipulation language is that of Structured Query Language (SQL), which is used to retrieve and manipulate data in a relational database.
● Other forms of DML are those used by IMS/DLI, CODASYL databases, such as IDMS and others.
 Question 10
A tuple in relation DBMS is a equivalent to
 A Record B Field C File D Database
Database-Management-System       Relational-Algebra
Question 10 Explanation:
A tuple in relation DBMS is a equivalent to record
Equivalent Database Concepts
Relation → Table
Tuple → Row or record
Attribute → Column or field
Cardinality → Number of rows
Degree → Number of columns
Primary key → Unique identifier
Domain → Pool of legal values
 Question 11
Which of the following is/are tautology?
 A a V b → b ⋀ c B a ⋀ b → b V c C a V b → (b → c) D a → b → (b → c)
Engineering-Mathematics       Propositional-Logic
Question 11 Explanation:

 Question 12
The number of circuits in a tree with 'n' nodes is
 A Zero B One C n-1 D n/2
Engineering-Mathematics       Graph-Theory
Question 12 Explanation:
● A tree (e.g. a binary tree) has a root, branches (nodes), and leaf nodes.
● A circuit in such a tree is impossible (unless you have some other data structure as well such as a linked list or you just program the tree so badly it ends up with circuits).
 Question 13
A complete graph with "n" vertices is
 A 2-chromatic B (n/2) chromatic C (n-1) chromatic D n-Chromatic
Engineering-Mathematics       Graph-Theory
Question 13 Explanation:

 Question 14
Which of the following circuit can be used as parallel to serial converter?
 A Multiplexer B Demultiplexer C Decoder D Digital Counter
Digital-Logic-Design       Combinational-Circuits
Question 14 Explanation:
In multiplexer, different inputs are inserted parallely and then it gives one output which is in serial form.
 Question 15
Minimum number of colours required to colour the vertices of a cycle with n nodes in such a way that no two adjacent nodes have the same colour is
 A 2 B 3 C 4 D n-2⌈(n/2)⌉+2
Engineering-Mathematics       Graph-Theory
Question 15 Explanation:
We need 3 colors to color a odd cycle and 2 colors to color an even cycle.
 Question 16
The number of full and half adders required to add 16-bit numbers is
Question 16 Explanation:
One half adder can add the least significant bit of the two numbers whereas full adders are required to add the remaining 15 bits as they all involve adding carries.
 Question 17
Which of the following expression is not equivalent to ~x?
 A x NAND x B x NOR x C x NAND 1 D X NOR 1
Question 17 Explanation:
 Question 18
Which one of the following set of gates are best suited for parity checking and parity generation
 A AND,OR,NOT gates B EX-NOR or EX-OR gates C AND gates D NOR gates
Digital-Logic-Design       Logic-Gates
Question 18 Explanation:
Parity generation : EXNOR
The XNOR gate will emit 1 only when there is not exactly one 1 input.
This feature can be used for parity generation.
Suppose A wants to send 1001. XNOR gate will give parity as 0.
But if A sends 1000 XNOR gate gives 1 as parity
Parity check: EXOR
B computes parity: 1+0+0+1+0 (mod 2) = 0
 Question 19
The register which keeps track of the execution of a program and which contains the memory address of the instruction currently being execution is called
 A Index register B Memory address register C Program counter D Instruction register
Computer-Organization       Registers
Question 19 Explanation:
● A program counter is a register in a computer processor that contains the address (location) of the instruction being executed at the current time.
● As each instruction is fetched, the program counter increases its stored value by 1.
● After each instruction is fetched, the program counter points to the next instruction in the sequence. When the computer restarts or is reset, the program counter normally reverts to 0.
 Question 20
The register which holds the address of the location to or from which data are to be transferred is called
 A index register B instruction register C memory address register D memory data register
Computer-Organization       Registers
Question 20 Explanation:
● The Memory Address Register (MAR) is the CPU register that either stores the memory address from which data will be fetched from the CPU, or the address to which data will be sent and stored.
● In other words, MAR holds the memory location of data that needs to be accessed. When reading from memory, data addressed by MAR is fed into the MDR (memory data register) and then used by the CPU. When writing to memory, the CPU writes data from MDR to the memory location whose address is stored in MAR. MAR which is found inside the CPU goes either to the RAM(Random Access Memory) or Cache.
● The Memory Address Register is half of a minimal interface between a microprogram and computer storage. The other half is a memory data register.
● In general, MAR is a parallel load register that contains the next memory address to be manipulated. For example, the next address to be read or written. is reset, the program counter normally reverts to 0.
 Question 21
In a binary max heap containing n numbers, the smallest element can be found in time
 A O(n) B O(logn) C O(loglogn) D O(A)
Data-Structures       Heap-Tree
Question 21 Explanation:
In Binary Max Heap, the smallest element will always be a leaf node either in left subtree or right subtree. So you have to traverse both left and right subtrees in each step to find the smallest element. So, it takes O(n) time.
 Question 22
Pseudo-instructions are
 A assembler directives B instructions in any program that have no corresponding machine code instruction C instruction in any program whose presence or absence will not change the output for any input D none of these
Compiler-Design       Assembler
Question 22 Explanation:
Pseudo Instructions are special commands to the assembler about the positioning of the program, the address the program should presumed to be assembled at, the name of the module, data declarations, the title and printing options for the program, defining and calling macros, macro looping and test, and end of source code. Unless a machine instruction is issued, these do not generate executable code.
 Question 23
The addressing mode used in the instruction PUSH B is
 A Direct B register C Register indirect D Immediate
Question 23 Explanation:
There are four types of instruction: –
PUSH A, PUSH B, add α popc
Wherein addressing mode used are as follows: –
PUSH A – Direct
PUSH B – Register
Pop.C – Immediate
 Question 24
Which of the following is the internal memory of the system(computer)?
 A CPU register B Cache C Main memory D All of these
Operating-Systems       File system-I/O-protection
Question 24 Explanation:
Types of Internal Memory:
● RAM
● ROM
 Question 25
The library function exit() causes an exit from the loop in which it occurs
 A The loop in which it occurs B The block in which it occurs C The function in which it occurs D none of these
C-Programming       Library-functions
Question 25 Explanation:

 Question 26
Queues serve major role in
 A Simulation of recursion B Simulation of arbitrary linked list C Simulation of limited resources allocation D Expression evaluation
Question 26 Explanation:
Recursion and Expression evaluation is implemented by using Stack.
 Question 27
A B-tree of order 4 is built from scratch by 10 successive insertions. What is the maximum number of node splitting operations that may take place?
 A 3 B 4 C 5 D 6
Database-Management-System       B-and-B+-Trees
Question 27 Explanation:
Total 5 splitting​ will occur during 10 successive insertions.
Let’s take 10 successive key values as {1, 2, 3, ... 10} which can cause maximum possible splits.

 Question 28
Can a DFA simulate NFA?
 A No B Yes C Sometimes D Depends on NFA
Theory-of-Computation       DFA
Question 28 Explanation:
In terms of power, they are equivalent and there is an algorithm (subset construction) for converting an NFA to an equivalent DFA. As you might tell from the algorithm's name, it constructs subsets of states of the NFA. If your NFA has n states, the algorithm may output a DFA with 2​ n​ states but that's an upper bound. Sometimes, the number of states does not change at all or even reduces. So in practice, it matters less as to which one to use.
 Question 29
(PVQ) ​ ⋀ ​ (P → R) ​ ⋀ ​ (Q → R) is equivalent to
 A P B Q C R D True≅T
Engineering-Mathematics       Propositional-Logic
Question 29 Explanation:
 Question 30
To sort many large object or structures, it would be most efficient to
 A Place reference to them in and array an sort the array B place them in a linked list and sort the linked list C place pointers to them in an array and sort the array D place them in an array and sort the array
Algorithms       Sorting
Question 30 Explanation:
Option-A is suitable for small amount of objects but not large
Option-B is not correct because it will extra time complexity and searching very difficult
Option-D is suitable for small amount of objects/elements
There are 30 questions to complete.