100+ JAC 12th Computer Science Important Question

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JAC 12th Computer Science Important Question
JAC 12th Computer Science Important Question

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JAC 12th Computer Science Important Question

Name of OrganisationJharkhand Academic Council, Ranchi
CategoryImportant Questions
ArticleJAC 12th Computer Science Important Question
Class12th
StreamScience
Question Type Objective(MCQ)
Subject Computer Science
Official Websitehttps://jac.jharkhand.gov.in/jac/
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1. Who invented C++?
a) Dennis Ritchie
b) Ken Thompson
c) Brian Kernighan
d) Bjarne Stroustrup

view answer

Answer: d
Explanation: Bjarne Stroustrup is the original creator of C++ in 1979 at AT&T Bell Labs.

2. What is C++?
a) C++ is an object oriented programming language
b) C++ is a procedural programming language
c) C++ supports both procedural and object oriented programming language
d) C++ is a functional programming language

view answer

Answer: c
Explanation: C++ supports both procedural(step by step instruction) and object oriented programming (using the concept of classes and objects).

3. Which of the following is the correct syntax of including a user defined header files in C++?
a) #include [userdefined]
b) #include “userdefined”
c) #include <userdefined.h>
d) #include <userdefined>

View Answer

Answer: b
Explanation: C++ uses double quotes to include a user-defined header file. The correct syntax of including user-defined is #include “userdefinedname”.

4. Which of the following is used for comments in C++?
a) /* comment */
b) // comment */
c) // comment
d) both // comment or /* comment */

view answer

Answer: d

Explanation: Both the ways are used for commenting in C++ programming. // is used for single line comments and /* … */ is used for multiple line comments

5. Which of the following user-defined header file extension used in c++?
a) hg
b) cpp
c) h
d) hf

view answer

Answer: c
Explanation: .h extensions are used for user defined header files. To include a user defined header file one should use #include”name.h” i.e. enclosed within double quotes.

Also Read –

6. Which of the following is a correct identifier in C++?
a) VAR_1234
b) $var_name
c) 7VARNAME
d) 7var_name

view answer

Answer: a
Explanation: The rules for writing an identifier is as follows:
i) may contain lowercase/uppercase letters, digits or underscore(_) only
ii) should start with a non-digit character
iii) should not contain any special characters like @, $, etc.

7. Which of the following is not a type of Constructor in C++?
a) Default constructor
b) Parameterized constructor
c) Copy constructor
d) Friend constructor

view answer

Answer: d
Explanation: Friend function is not a constructor whereas others are a type of constructor used for object initialization.

8. Which of the following approach is used by C++?
a) Left-right
b) Right-left
c) Bottom-up
d) Top-down

view answer

Answer: c
Explanation: C++ is an object-oriented language and OOL uses a bottom-up approach to solve/view a problem.

9. What is virtual inheritance in C++?
a) C++ technique to enhance multiple inheritance
b) C++ technique to ensure that a private member of the base class can be accessed somehow
c) C++ technique to avoid multiple inheritances of classes
d) C++ technique to avoid multiple copies of the base class into children/derived class

view answer

Answer: d
Explanation: Virtual inheritance is a C++ technique with which it ensures that a derived class contains only one copy of the base class’s variables. Refer Wikipedia for more info.

10. What happens if the following C++ statement is compiled and executed?

int *ptr = NULL;

delete ptr;

a) The program is not semantically correct
b) The program is compiled and executed successfully
c) The program gives a compile-time error
d) The program compiled successfully but throws an error during run-time

view answer

Answer: b
Explanation: The above statement is syntactically and semantically correct as C++ allows the programmer to delete a NULL pointer, therefore, the program is compiled and executed successfully.

11. What will be the output of the following C++ code?

#include <iostream>

#include <string>

using namespace std;

int main(int argc, char const *argv[])

{

     char s1[6] = “Hello”;

     char s2[6] = “World”;

     char s3[12] = s1 + ” ” + s2;

     cout<<s3;

     return 0;

}

a) Hello
b) World
c) Error
d) Hello World

view answer

Answer: c
Explanation: There is no operation defined for the addition of character array in C++ hence the compiler throws an error as it does not understood what to do about this expression.

12. What is the difference between delete and delete[] in C++?
a) delete is syntactically correct but delete[] is wrong and hence will give an error if used in any case
b) delete is used to delete normal objects whereas delete[] is used to pointer objects
c) delete is a keyword whereas delete[] is an identifier
d) delete is used to delete single object whereas delete[] is used to multiple(array/pointer of) objects

view answer

Answer: d
Explanation: delete is used to delete a single object initiated using new keyword whereas delete[] is used to delete a group of objects initiated with the new operator.

13. What happens if the following program is executed in C and C++?

#include <stdio.h>

int main(void)

{

     int new = 5;

     printf(“%d”, new);

}

a) Error in C and successful execution in C++
b) Error in both C and C++
c) Error in C++ and successful execution in C
d) A successful run in both C and C++

view answer

Answer: c
Explanation: new is a keyword in C++, therefore, we cannot declare a variable with name new but as there is no such keyword new in C, therefore, the program is compiled and executed successfully in C.

14. What happens if the following program is executed in C and C++?

#include <stdio.h>

void func(void)

{

     printf(“Hello”);

}

void main()

{

     func();

     func(2);

}

a) Outputs Hello twice in both C and C++
b) Error in C and successful execution in C++
c) Error in C++ and successful execution in C
d) Error in both C and C++

view answer

Answer: d
Explanation: As the func(void) needs no argument during its call, hence when we are calling func(2) with 2 as passed as a parameter then this statement gives the error in both C++ and C compiler.

15. Which of the following is correct about this pointer in C++?
a) this pointer is passed as a hidden argument in all static variables of a class
b) this pointer is passed as a hidden argument in all the functions of a class
c) this pointer is passed as a hidden argument in all non-static functions of a class
d) this pointer is passed as a hidden argument in all static functions of a class

view answer

Answer: c
Explanation: As static functions are a type of global function for a class so all the object shares the common instance of that static function whereas all the objects have there own instance for non-static functions and hence they are passed as a hidden argument in all the non-static members but not in static members.

16. What will be the output of the following C++ code?

  1.     #include <iostream>
  2.     #include <string>
  3.     #include <algorithm>
  4.     using namespace std;
  5.     int main()
  6.     {
  7.         string s = “spaces in text”;
  8.         s.erase(remove(s.begin(), s.end(), ‘ ‘ ), s.end() ) ;
  9.         cout << s << endl;
  10.     }

a) spacesintext
b) spaces in text
c) spaces
d) spaces in

view answer

Answer: a
Explanation: In this program, We formed a algorithm to remove spaces in the string.
Output:

$ g++ dan.cpp

$ a.out

spacesintext

17. Which of the following C++ code will give error on compilation?

================code 1=================

#include <iostream>

using namespace std;

int main(int argc, char const *argv[])

{

     cout<<“Hello World”;

     return 0;

}

========================================

================code 2=================

#include <iostream>

int main(int argc, char const *argv[])

{

     std::cout<<“Hello World”;

     return 0;

}

========================================

a) Code 1 only
b) Neither code 1 nor code 2
c) Both code 1 and code 2
d) Code 2 only

view answer

Answer: b
Explanation: Neither code 1 nor code 2 will give an error as both are syntactically correct as in first code we have included namespace std and in second one we have used scope resolution operator to resolve the conflict.

18. Which of the following type is provided by C++ but not C?
a) double
b) float
c) int
d) bool

view answer

Answer: d
Explanation: C++ provides the boolean type to handle true and false values whereas no such type is provided in C.

19. What is the value of p in the following C++ code snippet?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int main()
  4.     {
  5.         int p;
  6.         bool a = true;
  7.         bool b = false;
  8.         int x = 10;
  9.         int y = 5;
  10.         p = ((x | y) + (a + b));
  11.         cout << p;
  12.         return 0;
  13.     }

a) 12
b) 0
c) 2
d) 16

view answer

Answer: d
Explanation: | means bitwise OR operation so x | y (0101 | 1010) will be evaluated to 1111 which is integer 15 and as a is true and b is false so a+b(1 + 0) = 1. So final value of expression in line #10 will be 15 + 1 = 16.

20. By default, all the files in C++ are opened in _________ mode.
a) Binary
b) VTC
c) Text
d) ISCII

view answer

Answer: c
Explanation: By default, all the files in C++ are opened in text mode. They read the file as normal text.

21. What will be the output of the following C++ function?

  1.     int main()
  2.     {
  3.         register int i = 1;
  4.         int *ptr = &i;
  5.         cout << *ptr;
  6.      return 0;
  7.     }

a) Runtime error may be possible
b) Compiler error may be possible
c) 1
d) 0

view answer

Answer: b
Explanation: Using & on a register variable may be invalid, since the compiler may store the variable in a register, and finding the address of it is illegal.

22. Which of the following correctly declares an array in C++?
a) array{10};
b) array array[10];
c) int array;
d) int array[10];

view answer

Answer: d
Explanation: Because array variable and values need to be declared after the datatype only.

23. What is the size of wchar_t in C++?
a) Based on the number of bits in the system
b) 2 or 4
c) 4
d) 2

view answer

Answer: a
Explanation: Compiler wants to make CPU as more efficient in accessing the next value.

24. What will be the output of the following C++ code?

#include<iostream>

using namespace std;

int main ()

{

   int cin;

   cin >> cin;

   cout << “cin: ” << cin;

   return 0;

}

a) Segmentation fault
b) Nothing is printed
c) Error
d) cin: garbage value

view answer

Answer: d
Explanation: cin is a variable hence overrides the cin object. cin >> cin has no meaning so no error.

25. What is the use of the indentation in c++?
a) r distinguishes between comments and inner data
b) distinguishes between comments and outer data
c) distinguishes between comments and code
d) r distinguishes between comments and outer data

view answer

Answer: c
Explanation: To distinguish between different parts of the program like comments, codes, etc.

26. Which is more effective while calling the C++ functions?
a) call by object
b) call by pointer
c) call by value
d) call by reference

view answer

Answer: d
Explanation: In the call by reference, it will just passes the reference of the memory addresses of passed values rather than copying the value to new memories which reduces the overall time and memory use.

27. What will be the output of the following C++ program?

#include <iostream>

#include <string>

#include <cstring>

using namespace std;

int main(int argc, char const *argv[])

{

     const char *a = “Hello\0World”;

     cout<<a;

     return 0;

}

a) Hello
b) World
c) Error
d) Hello World

view answer

Answer: a
Explanation: char* are terminated by a ‘\0’ character so the string “Hello\0World” will be cut down to “Hello”.

28. Which of the following is used to terminate the function declaration in C++?
a) ;
b) ]
c) )
d) :

view answer

Answer: a
Explanation: ; semicolon is used to terminate a function declaration statement in C++.

29. What will be the output of the following C++ code?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int main()
  4.     {
  5.         char c = 74;
  6.         cout << c;
  7.         return 0;
  8.     }

a) I
b) J
c) A
d) N

view answer

Answer: b
Explanation: The literal value for 74 is J. So it will be printing J.

30. What will be the output of the following C++ program?

  1.     #include <iomanip>
  2.     #include <iostream>
  3.     using namespace std;
  4.     int main()
  5.     {
  6.         cout << setprecision(17);
  7.         double d = 0.1;
  8.         cout << d << endl;
  9.         return 0;
  10.     }

a) compile time error
b) 0.100001
c) 0.11
d) 0.10000000000000001

view answer

Answer: d
Explanation: The double had to truncate the approximation due to its limited memory, which resulted in a number that is not exactly 0.1.
Output:

$ g++ float2.out

$ a.out

0.10000000000000001

31. Which keyword is used to define the macros in c++?
a) #macro
b) #define
c) macro
d) define

view answer

Answer: b
Explanation: #define is the keyword that is used to define the macros in c++.

32. What is the correct syntax of accessing a static member of a class in C++?

—————————

Example class:

class A

{

     public:

          static int value;

}

—————————

a) A->value
b) A^value
c) A.value
d) A::value

view answer

Answer: d
Explanation: Scope resolution operator(::) is used to access a static member of a class.

33. The C++ code which causes abnormal termination/behaviour of a program should be written under _________ block.
a) catch
b) throw
c) try
d) finally

view answer

Answer: c
Explanation: Code that leads to the abnormal termination of the program should be written under the try block.

34. What is Inheritance in C++?
a) Deriving new classes from existing classes
b) Overloading of classes
c) Classes with same names
d) Wrapping of data into a single class

view answer

Answer: a
Explanation: Inheritance is the concept of OOPs in which new classes are derived from existing classes in order to reuse the properties of classes defined earlier.

35. What will be the output of the following C++ code?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int main()
  4.     {
  5.         int a = 5;
  6.         float b;
  7.         cout << sizeof(++a + b);
  8.         cout << a;
  9.         return 0;
  10.     }

a) 2 5
b) 4 5
c) 4 6
d) 2 6

view answer

Answer: b
Explanation: The a as a integer will be converted to float while calculating the size. The value of any variable doesn’t modify inside sizeof operator. Hence value of variable a will remain 5.
Output:

$ g++ size3.cpp

$ a.out

4 5

36. Which of the following symbol is used to declare the preprocessor directives in C++?
a) $
b) ^
c) #
d) *

view answer

Answer: c
Explanation: # symbol is used to declare the preprocessor directives.

37. What will be the output of the following C++ program?

#include<iostream>

using namespace std;

int main()

{

     int a = 5;

     auto check = [=]()

        {

          a = 10;

     };

     check();

     cout<<“Value of a: “<<a<<endl;

     return 0;

}

a) Segmentation fault
b) Value of a: 5
c) Value of a: 10
d) Error

view answer

Answer: d
Explanation: As this lambda expression is capturing the extrenal variable by value therefore the value of a cannot be changes inside the lambda expression hence the program gives error.

38. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

void square (int *x, int *y)

{

     *x = (*x) * –(*y);

}

int main ( )

{

     int number = 30;

     square(&number, &number);

     cout << number;

     return 0;

}

a) 30
b) Error
c) Segmentation fault
d) 870

view answer

Answer: d
Explanation: As we are passing value by reference therefore the change in the value is reflected back to the passed variable number hence value of number is changed to 870.

39. What is meant by a polymorphism in C++?
a) class having only single form
b) class having four forms
c) class having many forms
d) class having two forms

view answer

Answer: c
Explanation: Polymorphism is literally meant class having many forms.

40. What will be the output of the following C++ program?

#include <iostream>

#include <string>

using namespace std;

int main ()

{

  std::string str (“Sanfoundry.”);

  str.back() = ‘!’;

  std::cout << str << endl;

  return 0;

}

a) Sanfoundry!
b) Sanfoundry!.
c) Sanfoundry.
d) Sanfoundry.!

view answer

Answer: a
Explanation: back() function modifies the last character of the string with the character provided.

41. Pick the incorrect statement about inline functions in C++?
a) Saves overhead of a return call from a function
b) They are generally very large and complicated function
c) These functions are inserted/substituted at the point of call
d) They reduce function call overheads

view answer

Answer: b
Explanation: Inline are functions that are expanded when it is called. The whole code of the inline function gets inserted/substituted at the point of call. In this, they help in reducing the function call overheads. Also they save overhead of a return call from a function. Inline functions are generally kept small.

42. What will be the output of the following C++ program?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int main()
  4.     {
  5.         int n = 5;
  6.         void *p = &n;
  7.         int *pi = static_cast<int*>(p);
  8.         cout << *pi << endl;
  9.         return 0;
  10.     }

a) 5
b) 6
c) compile time error
d) runtime error

view answer

Answer: a
Explanation: We just casted this from void to int, so it prints 5
Output:

$ g++ poi1.cpp

$ a.out

5

43. What is abstract class in C++?
a) Any Class in C++ is an abstract class
b) Class from which any class is derived
c) Class specifically used as a base class with atleast one virtual functions
d) Class specifically used as a base class with atleast one pure virtual functions

view answer

Answer: d
Explanation: An abstract class is defined as a class which is specifically used as a base class. An abstract class should have atleast one pure virtual function.

44. Which of the following constructors are provided by the C++ compiler if not defined in a class?
a) Copy constructor
b) Default constructor
c) Assignment constructor
d) All of the mentioned

view answer

Answer: d
Explanation: If a programmer does not define the above constructors in a class the C++ compiler by default provides these constructors to avoid error on basic operations.

45. What will be the output of the following C++ program?

#include <iostream>

using namespace std;

int main()

{

    try

    {

        try

        {

            throw 20;

        }

        catch (int n)

        {

            cout << “Inner Catch\n“;

            throw;

        }

    }

    catch (int x)

    {

        cout << “Outer Catch\n“;

    }

    return 0;

}

a) Outer Catch
b)

Inner Catch

Outer Catch

c) Error
d) Inner Catch

view answer

Answer: b
Explanation: The exception thrown by the inner try catch block is caught by the inner block hence “Inner Catch” is printed but as inner catch block again throws an exception further therefore the exception is thrown further which is caught by the outer catch block hence “Outer Catch” is also printed.

46. Which concept allows you to reuse the written code in C++?
a) Inheritance
b) Polymorphism
c) Abstraction
d) Encapsulation

view answer

Answer: a
Explanation: Inheritance allows you to reuse your already written code by inheriting the properties of written code into other parts of the code, hence allowing you to reuse the already written code.

47. What will be the output of the following C++ code snippet?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int operate (int a, int b)
  4.     {
  5.         return (a * b);
  6.     }
  7.     float operate (float a, float b)
  8.     {
  9.         return (a / b);
  10.     }
  11.     int main()
  12.     {
  13.         int x = 5, y = 2;
  14.         float n = 5.0, m = 2.0;
  15.         cout << operate(x, y) <<“\t“;
  16.         cout << operate (n, m);
  17.         return 0;
  18.     }

a) 10.0 5
b) 10 2.5
c) 10.0 5.0
d) 5.0 2.5

view answer

Answer: b
Explanation: In this program, we are divide and multiply the values.
Output:

$ g++ over3.cpp

$ a.out

10   2.5

48. How structures and classes in C++ differ?
a) Structures by default hide every member whereas classes do not
b) In Structures, members are public by default whereas, in Classes, they are private by default
c) Structures cannot have private members whereas classes can have
d) In Structures, members are private by default whereas, in Classes, they are public by default

view answer

Answer: b
Explanation: Structure members are public by default whereas, class members are private by default. Both of them can have private and public members.

49. What will be the output of the following C++ code?

  1.     #include <iostream>
  2.     using namespace std;
  3.     int main ()
  4.     {
  5.         int a, b, c;
  6.         a = 2;
  7.         b = 7;
  8.         c = (a > b) ? a : b;
  9.         cout << c;
  10.         return 0;
  11.     }

a) 12
b) 14
c) 6
d) 7

view answer

Answer: d
Explanation: We are using the ternary operator to evaluate this expression. It will return first option, if first condition is true otherwise it will return second
Output:

$ g++ ess1.cpp

$ a.out

7

50. What is the benefit of c++ input and output over c input and output?

a) Both Type safety & Exception
b) Sequence container
c) Exception
d) Type safety

view answer

Answer: d
Explanation: C++ input and output are type safety that means we don’t need to specify the type of variable we are printing.
eg:
in C we need to specify %d showing that an integer will be printed, whereas in C++ we just cout the variable.
printf(“%d”, a);
cout<<a;

51. What will be the output of the following C++ code snippet?

  1.     #include <stdio.h>
  2.     #include<iostream>
  3.     using namespace std;
  4.     int main ()
  5.     {
  6.         int array[] = {0, 2, 4, 6, 7, 5, 3};
  7.         int n, result = 0;
  8.         for (n = 0; n < 8; n++)
  9.         {
  10.             result += array[n];
  11.         }
  12.         cout << result;
  13.         return 0;
  14.     }

a) 21
b) 27
c) 26
d) 25

view answer

Answer: b
Explanation: We are adding all the elements in the array and printing it. Total elements in the array is 7, but our for loop will go beyond 7 and add a garbage value.

52. What will be the output of the following C++ program?

  1.     #include <iostream>
  2.     #include <string>
  3.     using namespace std;
  4.     int main ()
  5.     {
  6.         string str (“Sanfoundry”);
  7.         for (size_t i = 0; i < str.length();)
  8.         {
  9.             cout << str.at(i-1);
  10.         }
  11.         return 0;
  12.     }

a) runtime error
b) Sanfo
c) S
d) Sanfoundry

view answer

Answer: a
Explanation: This program will terminate because the cout element is out of range.

53. What will be the output of the following C++ program?

#include <iostream>

using namespace std;

class A{

public:

     A(){

          cout<<“Constructor called\n“;

        }

     ~A(){

          cout<<“Destructor called\n“;

         }

};

int main(int argc, char const *argv[])

{

     A *a = new A[5];

     delete[] a;

     return 0;

}

a) Segmentation fault
b) “Constructor called” five times and then “Destructor called” five times
c) “Constructor called” five times and then “Destructor called” once
d) Error

view answer

Answer: b
Explanation: In the above program we have first initiated five-pointer variables using new keyword hence fives time constructor will be called after that as we using delete[] (used for deleting multiple objects) to delete variables hence all the five objects created will be destroyed and hence five times destructor will be called.

  1. In C++ every statement end with
    (a)colon(:)
    (b)Comma (,)
    (c)dot (.)
    (d)Semicolon (;)

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d

  1. Base class is
    (a)normal class
    (b)derived class
    (c)child class
    (d)all of these

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a

  1. Which of the following is not a feature of C++.
    (a)Operator overloading
    (b)Inheritance
    (c)Namespace
    (d)Reflection

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d

  1. Which of the following is not a member of the class?
    (a)Static function
    (b)Friend function
    (c)Virtual function
    (d)Const function

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d

  1. Which of the following is the correct class of the object cout?
    (a)iostream
    (b)istream
    (c)ostream
    (d)ifstream

view answer

c

  1. Which of the following is not a type of inheritance?
    (a)Multiple
    (b)Multilevel
    (c)Distributive
    (d)Hierarchical

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c

  1. In protected inheritance, a public data member of the base class will be treated in a derived class as.
    (a)public
    (b)private none of the above
    (c)protected
    (d)none of the above

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a

  1. main is a/an
    (a)keyword
    (b)object
    (c)function
    (d)none of the above

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c

  1. A set of arithmetic operators are.
    (a)+ , – , * , / , %
    (b)< , > , >= , <=
    (c)&&, ||, !
    (d)none of the above

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c

  1. A set of logical operators are.
    (a)+ , – , * , / , %
    (b)< , > , >= , <=
    (c)&&, ||, !
    (d)none of the above

view answer

c

  1. Which of the following concepts means determining at runtime what method to invoke.
    (a)Data hiding
    (b)Dynamic loading
    (c)Dynamic typing
    (d)Dynamic binding

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d

  1. is a way of combining data with functions into an object.
    (a)Object
    (b)Encapsulation
    (c)Inheritance
    (d)Constructor

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b

  1. eof is an acronym of
    (a)the ending of line
    (b)ending of files
    (c)end of file
    (d)None of the above

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c

  1. C++ language has been developed by
    (a)Dennis Ritchie
    (b)Ken Thompson
    (c)Martin Richard
    (d)Bjarne Stroustrup

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d

  1. Which operator has the lowest precedence?
    (a)Size
    (b)Urinary
    (c)Assignment
    (d)Comma

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c

  1. The ternary operator operates on how many operands?
    (a)1
    (b)2
    (c)3
    (d)4

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c

  1. An instance of a class is called…….
    (a)private
    (b)object
    (c)public
    (d)None of the above

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c

  1. Which of the following library function below by default aborts the Program.
    (a)end ( )
    (b)terminate ( )
    (c)abort ( )
    (d)exit ( )

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d

  1. The individual elements in an array are called
    (a)encrypted
    (b)Decrypted
    (c)Subscripted
    (d)Identifier

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c

  1. The default access level assigned to members of the class is.
    (a)Private
    (b)Public
    (c)Protected
    (d)None of these

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a

  1. while loop is a …. controlled loop.
    (a)count
    (b)exit
    (c)entry
    (d)none of the above

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c

  1. The do-while loop is a …….. Controlled loop.
    (a)count
    (b)exit
    (c)entry
    (d)none of the above

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c

  1. Which of the following is an abstract data type?
    (a)int
    (b)string
    (c)double
    (d)class

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b

  1. For loop is a ….. Controlled loop.
    (a)count
    (b)exit
    (c)entry
    (d)none of the above

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a

  1. Which of the following approach is adopted by C++
    (a)Bottom-up
    (b)Top-down
    (c)Right-left
    (d)Left-right

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a

  1. Which of the following is the symbol for AND operator?
    (a)ll
    (b)&&
    (c)&
    (d)None of these

Title for This Block

b

  1. cout is a/an ………..
    (a)operator
    (b)object
    (c)function
    (d)macro

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c

  1. Which operator has the lowest precedence?
    (a)size
    (b)Unary
    (c)Assignment
    (d)Comma

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c

  1. In object-oriented programming, by wrapping up Characteristic and behavior into one unit, we achieve.
    (a)Data Abstraction
    (b)Data Encapsulation
    (c)Data hiding
    (d)All of these

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b

  1. The use of the break statement in a switch statement is.
    (a)optional
    (b)compulsory
    (c)to check an error
    (d)none of these

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b

  1. Which of the following sorting algorithms divide-and-conquer type?
    (a)Bubble sort
    (b)Insertion sort
    (c)Quicksort
    (d)All of the above

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c

  1. Which of the following data structure is a linear data structure?
    (a)Trees
    (b)Graphs
    (c)Arrays
    (d)None of the above

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c

  1. Which data structure allows deleting data elements from front and inserting at the rear?
    (a)Stacks
    (b)Queues
    (c)Deques
    (d)Binary search tree

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b

  1. The operation of processing each element in the list is known as
    (a)Sorting
    (b)Merging
    (c)Inserting
    (d)Traversal

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d

  1. Which of the following is not the type of queue?
    (a)Ordinary queue
    (b)Single-ended queue
    (c)Circular queue
    (d)Priority queue

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a

  1. How many nodes does a binomial tree of the order have?
    (a)0
    (b)1
    (c)2
    (d)3

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a

  1. Quicksort is faster than
    (a)Selection sort
    (b)Insertion sort
    (c)Bubble sort
    (d)All of these

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d

  1. Which type of linked does not store NULL in the next field?
    (a)Singly-linked list
    (b)Doubly linked list
    (c)Circular linked list
    (d)All of these

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c

  1. Disk piled up one above the other represent a
    (a)Stacks
    (b)Queues
    (c)Linked list
    (d)Array

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a

  1. Major operation performed on Data Structures are
    (a)Sorting
    (b)Searching
    (c)Inserting
    (d)All the above

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d

  1. Arranging elements of an array in a specific order is called
    (a)Sorting
    (b)searching
    (c)Inserting
    (d)Traversing

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a

  1. Processing all the elements of an array is called.
    (a)Insertion
    (b)Sorting
    (c)Deletion
    (d)Traversing

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d

  1. Which of the following data structures are indexed structures?
    (a)Linear arrays
    (b)Linked list
    (c)Queue
    (d)Stack

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b

  1. LIFO means
    (a)Last In First Out
    (b)Last In Fast Overflow
    (c)Last In First Overflow
    (d)None of the above

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a

  1. FIFO means
    (a)First In First Out
    (b)Fast In Fast Out
    (c)Fast In First Out
    (d)First In Fast Out

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a

  1. Which of the following data structures cant store the non-homogeneous data elements?
    (a)Arrays
    (b)Pointers
    (c)Records
    (d)None

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d

  1. A stack is a …….. data Structure.
    (a)Dynamic
    (b)Linear
    (c)Non-dynamic
    (d)None of the above

View answer

b

  1. Queue is work as.
    (a)FIFO
    (b)LIFO
    (c)Both a and b
    (d)None of the above
  1. Elements can be added or removed at both ends is called
    (a)Queue
    (b)Deque
    (c)Circular Queue
    (d)All the above
  1. Stack is work as.
    (a)FIFO
    (b)LIFO
    (c)Both a and b
    (d)None of the above
  1. Deleting from an empty list is known as.
    (a)Overflow
    (b)Underflow
    (c)Both (a) and (b)
    (d)None of the above
  1. A line in a grocery store represents a
    (a)Stacks
    (b)Linked list
    (c)Queues
    (d)Array
  1. In a queue, insertion is done at.
    (a)Rear
    (b)Front
    (c)Both (a) and (b)
    (d)n (d)one of the above
  1. Which data structure allows deleting data elements from front and inserting at the rear?
    (a)Stacks
    (b)Deques
    (c)Queues
    (d)Binary search tree
  1. Which of the following data structure is non-linear type?
    (a)Strings
    (b)Stacks
    (c)Lists
    (d)None of above
  1. Beginning address of an array is called
    (a)Base Address
    (b)Top Address
    (c)Both (a) & (b)
    (d)None of the above
  1. Transform prefix operation /- + A*BCD * EF to an infix form
    (a)(A + B * C – D) /E * F
    (b)(A+ B – C / D) * E *F
    (c)(A + B – C * D) /E * F
    (d)None of the above
  1. Transform infix operation (A+ B * C- D) /E * F to an postfix form
    (a)A B C+ * D – EF / (b)A B C + D – EF * /
    (c)A B C * + D – EF / *
    (d)None of the above

113.Key is an ….. in the database system.
(a)Attribute
(b)Condition
(c)Row
(d)Variables

  1. Ordered by clause is used to ….. the query result.
    (a)sort
    (b)index
    (c)order
    (d)none of the above
  1. A…….. is used to identify a particular record.
    (a)Index
    (b)Tuple
    (c)Key
    (d)All the above
  1. A row in a relation is called
    (a)Data
    (b)Domain
    (c)Tuple
    (d)None of the above
  1. The duplication of data is known as.
    (a)Data redundancy
    (b)Attribute
    (c)domain
    (d)None of these
  1. Set of possible values that an attribute can have……
    (a)Tuple
    (b)Value
    (c)Domain
    (d)None of the above
  1. A…….. is an integrated collection of related files.
    (a)Database
    (b)Software
    (c)Record
    (d)All the above
  1. The number of tuples in a relation is called.
    (a)Degree
    (b)Attribute
    (c)Cardinality
    (d)None of the above
  1. The following are components of a database except …….
    (a)user data
    (b)reports
    (c)metadata
    (d)indexes
  1. Which of the following is NOT a type of SQL constraint?
    (a)PRIMARY KEY
    (b)FOREIGN KEY
    (c)ALTERNATE KEY
    (d)UNIQUE
  1. Which of the following is a database element?
    (a)Data
    (b)Constraints and Schema
    (c)Relationships
    (d)All the above
  1. Which of the following is not a Data Manipulation Language Statement?
    (a)COMMIT
    (b)DELETE
    (c)UPDATE
    (d)INSERT
  1. SQL means.
    (a)Simple Query Language
    (b)Structured Quarter Language
    (c)Structured Query Language
    (d)None of the above
  1. DDL means.
    (a)Data Definition Language
    (b)Data Dictionary Language
    (c)Data Description Language
    (d)None of the above
  1. DML means.
    (a)Data Manipulation Language
    (b)Data Maintained Language
    (c)Data Multiple Language
    (d)None of the above
  1. RDBMS means
    (a)Relational Database Management System
    (b)Restricted Database Management System
    (c)Resolution Database Management System
    (d)All the above
  1. The number of tuples in a relation is called.
    (a)Degree
    (b)Attribute
    (c)Cardinality
    (d)None of the above
  1. A transparent DBMS?
    (a)Can not hide sensitive information from users
    (b)Keep its logical structure hidden from users
    (c)keeps its physical structure hidden from users
    (d)Both (b) and (c)
  1. How long is an IPv6 address?
    (a)32 bits
    (b)64 bits
    (c)146 bits
    (d)128 bits
  1. Virus, Worms and Trojan horse are examples of
    (a)Adware
    (b)Malware
    (c)Spyware
    (d)All of these
  1. A program that enables users to post messages or articles for other people to read.
    (a)Gopher
    (b)FTP
    (c)Newsgroup
    (d)Electronic Newspaper
  1. Web Browser is/are –
    (a)Google Chrome
    (b)Internet Explorer
    (c)Firefox
    (d)All the above
  1. MAN refers to
    (a)Mega Area Network
    (b)Medium Area Network
    (c)Mini Area Network
    (d)Metropolitan Area Network
  1. Co-axial cables are made of
    (a)Board
    (b)Base
    (c)Both a) & b)
    (d)None of the above
  1. SMTP means
    (a)Simple Mail Trapping Protocol
    (b)Simple Mail Transport Protocol
    (c)Simple Mail Transpose Protocol
    (d)Simple Mail Transfer Protocol
  1. GIAS means
    (a)Gateway Internet Access Service
    (b)Gateway Intranet Access Service
    (c)etaway Internet Access Service
    (d)None of the above
  1. Home page is in the form of
    (a)Text
    (b)Hyperlink
    (c)Hypertext
    (d)All the above
  1. A tool that makes the internet easy to work with.
    (a)Internet
    (b)Cable
    (c)Gopher
    (d)None of the above
  1. …….. was the first network based on TCP/IP.
    (a)NFS
    (b)ARPANET
    (c)NFSNET
    (d)ARCNET
  1. An interconnected collection of autonomous computers.
    (a)Bridge
    (b)Router
    (c)Network
    (d)None of these
  1. ……… is a network of networks.
    (a)Intranet
    (b)Webpage
    (c)Internet
    (d)Browser
  1. The data transmission rate is expected in……
    (a)Base
    (b)Baud
    (c)Amplitude
    (d)None of the above
  1. Which of the following layer is not in the OSI model?
    (a)Physical Layer
    (b)Network Layer
    (c)Internet Layer
    (d)Transport Layer
  1. An Internet utility used for remote login is.
    (a)Telnet
    (b)Cookies
    (c)Firewall
    (d)Crackers
  1. What protocol does PPP use to identify the Network layer protocol?
    (a)NCP
    (b)ISDN
    (c)LCP
    (d)HDLC
  1. Which protocol does DHCP use at the Transport layer?
    (a)IP
    (b)TCP
    (c)UDP
    (d)ARP
  1. Which of the following is the correct format of Email address?
    (a)www.nameofebsite.com
    (b)name.website.com
    (c)name@website@info
    (d)[email protected]
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JAC 12th Computer Science Important Question FAQS

Important MCQ Questions of Computer science for JAC board class 12

JAC Board Class 12th के लिए बहुत महत्वपूर्ण Question पर दिए गए हैं आप इससे पढ़ाई कर सकते हैं.

JAC Board 12th Computer Science Important Question Download

JAC Board की परीक्षा के लिए हमने यहां पर 100 प्लस महत्वपूर्ण प्रश्न दिए हैं जो की बोर्ड परीक्षा में पूछे जाते हैं या पूछे जा सकते हैं अगर आप यहां से प्रश्न को कर लेते हैं तो आप के परीक्षा में बहुत मदद मिलेगा.

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