Solve Questions on Computer Science Single choice answers

Multiple Choice Questions ( Single Choice) :-

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1) In SQL, which of the following is not a data Manipulation Language Commands?

A) Delete
B) Select
C) Update
D) Create
E)None of the above

Answer :- E)None of the above

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2) Which of the following is not a type of SQL statement?

A) Data Manipulation Language (DML)
B) Data Definition Language (DDL)
C)Data Control Language (DCL)
D)Data Communication Language (DCL)
E)None of these

Answer :- D) Data Communication Language

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3)Which of the following is not included in DML (Data Manipulation Language)

A)INSERT
B)UPDATE
C) DELETE
D)CREATE
E)None of these

Answer :-D)CREATE

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4)TRUNCATE statement in SQL is a -

A) DML statement
B) DDL statement
C) DCL statement
D)DSL statement
E)None of these

Answer:- B) DDL statement

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5) In SQL, which command is used to add new rows to a table?

A)Alter Table
B)Add row
C)Insert
D)Append
E)None of the Above

Answer :- C)Insert

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6) Stack is also called ____

A) First In First Out (LIFO)
B)Last In First Out (FIFO)
C)First In Last Out (FILO)
D)First Come First Served (FCFS)
E)None of the above

Answer :- C)First In Last Out (FILO)

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7)The full form of DDL is

A) Dynamic Data Language
B)Detailed Data Language
C)Data Definition Language
D)Data Derivation Language
E)All of these

Answer :- C)Data Definition Language

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8) The OSI model consists of ___layers.

A) Nine
B)Eight
C)Seven
D)Five
E)Eleven

Answer :- C)Seven

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9)Assembly language is a _____

A) Low Level Language
B)Middle Level Language
C)High level Language
D)User Language
E)None of these


Answer :- A) Low Level Language

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10) Which of the following is a type of translator?

A)Assembler
B)Compiler
C)Interpreter
D)All of the Above
E) None of these

Answer:-  C)  Interpreter

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11) Which of the following term is related to the stack?

 A) TOP
 B)PUSH
 C)POP
D)Rear
E) A, B and C.

Answer:-E) A, B and C.

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12) In Queues, the end from where items inserted is called

A) Rear
B) Front
C) Top
D) Base
E) None of these

Answer:- A) Rear

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13)Which protocol is used for browsing website:

A) TCP
B) FITFP
C)FTP
D)TFTP
E)None of these

Answer:-A) TCP

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13) Which of the following is a browser?

A) Netscape Navigator
B) Mosaic
C)Mozilla Firefox
D)Google chrome
E)All of these

Answer:- E)All of these

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14) Black Box Testing sometime called -

A) Data flow testing
B) Loop testing
C) Behavioral testing
D)Graph based testing
E)None of these

Answer:-D)Graph based testing

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15)The Objective of testing is

A)Debugging
B)To uncover errors
C) To gain modularity
D) To analyze system
E) None of these

Answer :-B) To uncover errors

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16)Choose the right sequence of SDLC (Software development life cycle) steps

A) Design, Requirement Analysis, Coding, Testing
B) Requirement Analysis, Design, Coding, Testing
C) Requirement Analysis, Design, Testing, Coding
D) Requirement Analysis, Coding, Design, Testing
E) None of these

Answer :-B) Requirement Analysis, Design, Coding, Testing

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17) ODBC is based on ___.

A) Structured Query Language.
B) C language
C) C++ language
D) .net
E)None of these

Answer:- A) Structured Query Language.

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18)JVM is a virtual machine that can execute ___
 A)C language
B).net programming
 C)RDBMS
 D)C++ Language
E)Java byte Code

Answer : E) Java byte Code

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19)Which of the following virus overtake computer system when it boots and destroy in-formation?

A)Trojan
B)System infectors
C)Boot infectors
D)Stealth virus
E) None of these

Answer :- C) Boot infectors

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20)The JDBC-ODBC bridge is

A) Three tiered
B)Multithread
C) Best for any platform
D) All of these
E) None of these

Answer :-B) Multithread

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DTE and DCE

Terms related to modem connectivity:-

DTE :-
Data Terminal Equipment, a device that controls data flowing to or from a computer. The term is most often used in reference to serial communications defined by the RS-232C standard. This standard defines the two ends of the communications channel as being a DTE.
      
              It converts user information into signals or reconverts received signals. These can also be called tail circuits. A DTE device communicates with the data circuit-terminating equipment (DCE). The DTE/DCE classification was introduced by IBM.

           
              A DTE is the functional unit of a data station that serves as a data source or a data sink and provides for the data communication control function to be performed in accordance with the link protocol.

DCE :-
Data Communications Equipment (DCE) device. In practical terms, the DCE is usually a modem and the DTE is the computer itself, or more precisely, the computer's UART chip. For internal modems, the DCE and DTE are part of the same device.


Modem -
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information and demodulates the signal to decode the transmitted information
     In modem for Broadband ,
                  ADSL (Asymmetric Digital Subscriber Line) modems, a more recent development,

SQL related terms DCL,DML,DDl,TCL

1)DDL 
 
Data Definition Language (DDL) statements are used to define the database structure or schema. Some examples: 
CREATE - to create objects in the database
ALTER - alters the structure of the database
DROP - delete objects from the database
TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
COMMENT - add comments to the data dictionary
RENAME - rename an object

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2)  DML

Data Manipulation Language (DML) statements are used for managing data within schema objects. Some examples:
SELECT - retrieve data from the a database
INSERT - insert data into a table
UPDATE - updates existing data within a table
DELETE - deletes all records from a table, the space for the records remain
MERGE - UPSERT operation (insert or update)
CALL - call a PL/SQL or Java subprogram
EXPLAIN PLAN - explain access path to data
LOCK TABLE - control concurrency

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3)  DCL

Data Control Language (DCL) statements. Some examples:
GRANT - gives user's access privileges to database
REVOKE - withdraw access privileges given with the GRANT command

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4)  TCL

Transaction Control (TCL) statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions.
COMMIT - save work done
SAVEPOINT - identify a point in a transaction to which you can later roll back
ROLLBACK - restore database to original since the last COMMIT
SET TRANSACTION - Change transaction options like isolation level and what rollback segment to use

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Next

Mathematical Pre-requisities

Set:-
           Set is a collection of object without repetition and each object of set is called element of a set example D={x/x is a day of week}
Properties
1) Empty set  - It contains no elements denoted by ∅ {}.
2) Subset -  Set A is subset of B if every element in set A is in B denoted as A ⊂ B.
3) Equal sets -Two sets are equal if A ⊂ B and B ⊂ A..
4) Power set -A is a power set if 2^A.Set of all subsets A
        For example if,
           A={1,2,3}
           2^A={ {∅},{1},{2},{3},{1,2},{1,3},{2,3},{1,2,3} }
          2³=8 elements.
5) Compliment A' such that A'={x/x ∉ A}.
6) Union - A U B is all the elements in set A and B.
7) Intersection -A ∩ B is the element s both which is in A  and also in B.
8) Cardinality is the number of sets.


Relation :-  A relation R in set S is collection of ordered pair of elements in S.
Properties :-
1) Reflexive  -R is reflexive in S if xRx ∀ (for all) x ∈ S.
2) Symmetric -R is symmetric in x if xRy ⇒ yRx
3) Transitivie - R is transitive in x if xRy and yRz ⇒xRz
4)Equivalence relation -If relation is all three reflexive,symmetric and transitive.

Compile,Link and Run

Compile,Link and Run
        When you're ready to compile HELLOMSG, you can  select Build Hellomsg.exe from the Build menu,or press F7,or  select the Build   icon from the Build  toolbar.The appearance of this  icon is  shown in the Build menu.If the Build  toolbar  is not currently  displaned,you can choose Customize from the Tools menu and select the Toolbars tab.Pick Build or Build MiniBar.

      Alternatively you can select Execute Hellomsg.exe from the Build menu ,or press Ctrl+F5 or click the Execute program icon which looks like red exclamation point from the Build toolbar.You ''ll get a message box asking you if you want to build the program .

       As normal ,during the compile stage ,the compiler generates an .OBJ (object) file from the C source code file.During the link stage the linker combines the .OBJ file with .LLB (library ) files to create the .EXE(executable) file .You can see a list of these library files by selecting Settings from the Project tab and clicking the Link tab .In particular ,you'll notice KERNEL32.LIB,USER.LIB,and GDI.LIB.These are "import libraries " for the three major Windows sub-systems.They contain dynamic -link library names and reference information that is bound into the .EXE file .Windows uses this information to resolve calls from the program  to functions KERNEL32.DLL,USER.DLL,and GDI.DLL. dynamic0link libraries.

          In the Visual C++ Developer Studio ,you can compile and link the program in different configurations .By defaiult ,these are called Debug and Release .The executable files are stored in subdirectories of these names .In the Debug configuration ,information is added to the .EXE file assists in deubgging the program  and in tracing through the program source code.
              
         

to be happy

 सुखी होने के दस उपाय। .......... 


१. काम में सदैव  व्यस्त रहो। 

२. अपनी क्षमता को पहिचानो। 

३. कभी कभी न बोलना भी सीखो। 

४. अपनी गलती स्वीकार करो। 

५. व्यवहारीक  बनो। 

६. सबको राय लेकर निर्णय लो। 

७. आए से जादा ख़र्च न करो। 

८. गहराई  से सोचो फिर बोलो। 

९. प्रतिक्षा  में धीरज रखो। 

१०. सबको सम्मान से बुलाओ। 

 

दुखी होने के दस कारण। ………………


१. देरी  से सोना और देरी से उठाना।
 
२.कोई  भी काम समय से न करना। 

३. किसीका भी विशवास न करना। 

 ४. सव्य  की  बात को ही सत्य बताना। 

५. कीसीके लिए कुछ  न करना। 

६. हमेशा सव्य  के लिए ही सोचना। 

७. लेन देन  का हिसाब ना रखना। 

८. बिना कारन झ़ुठ बोलना। 

९. बिना मांगे सलाह देना। 

१०. भुतकाल  के  सुख  को बहुत याद  करना। 
 

Pointers and void pointer and precedence of & and * operators in pointers.

Pointers
Definition:- A pointer is a variable that stores the memory address of another another variable.

void pointer :-( it can contain address of any data type )
syntax:-    void *pointer_name;
example:- void *v_ptr;
A void pointer does not have any data-type associated it with and can contain the address of any type of variable.
example:- void v_ptr;
                char ch;
                 int i;
                 float fvar;
                 v_ptr= &ch;
                 v_ptr= &i;
                 v_ptr =&fvar;

Precedence of & and * operator:-
Both are unary operators and have precedence equal to other unary operators.
Their associativity is from right to left.
example:-   int n=10,++*ptr;
                  ptr = &n;
                  ptr = 1024
                 
                   ++ *ptr =  ++(1024)
                                = ++(10)
                                = 11
  
                   *ptr++  = (*1024)++
                                =10 ++
                                =10

                    * ++ptr = *(++1024)
                                 = *(1026)
                                 = data at 1026