MBOSE Class 12 Question Paper 2020 for Computer Application

Total No. of Printed Pages—12
HS/XII/A.Sc.Com/CAP/OC/20

2020

COMPUTER APPLICATIONS
( Old Course )
( Arts / Science / Commerce )
( Theory )
Full Marks : 70
Time : 3 hours

The figures in the margin indicate full marks for the questions

General Instructions :
(i) Write all the answers in the Answer Script.
(ii) Attempt Part—A (Objective Questions) serially.
(iii) Attempt all parts of a question together at one place.
(iv) Part—A (Objective Questions) is to be attempted
according to stream as mentioned.
(v) Attempt Part—B [Descriptive (Unit—I)] according to
stream as mentioned.

( PART : A—OBJECTIVE )
( Marks : 35 )
SECTION—I
( Marks : 25 )

1. Fill in the blanks from the list of words/phrases given
below : 1×10=10
( For Science stream candidates only )
(a) When each term of a logic expression contains all
_____, it is said to be in canonical form.

/35 [ P.T.O.

( 2 )

(b) A _____ is an implicant which cannot be wholly
enclosed by a larger implicant.

(c) The logical OR of literals is called the _____ term.

(d) The expression a + a·b is equal to _____.

( For Arts / Commerce stream candidates only )

(a) _____ is a primary method of transferring files over
the Internet.

(b) _____ provides a grid for inputting tasks we need to
complete in our Web.

(c) _____ translates domain names to IP addresses.

(d) A / An _____ address is a numeric identifier
assigned to a computer on a network.

( For all Science / Arts / Commerce stream
candidates : C Language )

(e) A function that does not return anything has return
type _____.
(f) The _____ operator is unary operator to find the
address of a variable.
(g) The function _____ indicates an end-of-file condition
for any stream oriented data file.
(h) _____ function allows us to enter data from the
keyboard.
(i) ? : is a _____ expression.
(j) The expression 3*5%3 evaluates to _____.

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( 3 )

List of words / phrases :

product variables IP conditional
& http a+b Boolean
canonical * EOF scanf()
folder view non-prime prime ISP
implicant implicant
FTP a task view 6
DNS minterm sum void
int feof() printf() 0
report view Class A

2. State whether the following statements are True or
False : 1×10=10

( For Science stream candidates only )

(a) In a Karnaugh map, quad reduction makes a pair of
adjacent cells that contains the value 1.

(b) Product of sum is the sum (logical OR) of product
terms.

( For Arts / Commerce stream candidates only )

(a) Excite is one of the popular search engines.

(b) Using News Group, users anywhere on the Internet
can log into any other machine on which they have
an account.

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( 4 )

( For all Science / Arts / Commerce stream
candidates : C Language )

(c) The escape sequence ‘\v ’ stands for vertical tab.

(d) Every C program must have a main() function.

(e) If x is an integer variable and px is a pointer, the
statement
px = *x;
assigns the address of x to px.

(f) FILE is a structure which has been defined in the
stdio.h header file.

(g) Each case label in a switch statement must end with
semicolon.

(h) The operator i =+j is shorthand for i = i + j.

(i) “12,245” is a legal string constant.

(j) In case of call by reference, the parameter will be
always of pointer type.

3. Choose and write the correct answer : 1×5=5

( For Science stream candidates only )

(a) The expression ab  ab  is equal to
(i) a  b
(ii) a
(iii) 0
(iv) None of the above

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( 5 )

(b) When POS of logic expression is in canonical form,
each sum term is called
(i) minterm
(ii) maxterm
(iii) Both (i) and (ii)
(iv) None of the above

( For Arts / Commerce stream candidates only )

(a) The DNS system is a/an
(i) database
(ii) protocol
(iii) connectivity
(iv) Internet

(b) ISP stands for
(i) Internet Social Provider
(ii) Information Service Protocol
(iii) Internet Service Provider
(iv) Information Service Provider

( For all Science / Arts / Commerce stream
candidates : C Language )

(c) Void main() {
int k, i = 1;
k = 2  ++i;
printf(“%d”, k);
getch();
}

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( 6 )

What will be the output of the code?
(i) 2
(ii) 3
(iii) 6
(iv) 4

(d) Void main()
{
enum colors {pink, red, blue, green} c;
c = blue;
printf(“%d”, c);
getch();
}
What is the output of the above code?
(i) 2
(ii) Blue
(iii) 3
(iv) Both (i) and (ii)

(e) int i;
void main()
{
increment();
getch();
}
void increment()
{
printf(“%d”, i);
}

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( 7 )

What is the storage class of variable i ?
(i) Auto
(ii) Register
(iii) Static
(iv) Extern

SECTION—II
( Marks : 10 )

4. Answer any five of the following in not more than
3 to 4 sentences each : 2×5=10
( For Science stream candidates only )
(a) State De Morgan’s theorem.
(b) Verify the following using truth table :
a+ (b·c) = (a+b)(a+c)
( For Arts / Commerce stream candidates only )
(a) Write a note on WWW.
(b) Define Internet and its applications.
( For all Science / Arts / Commerce stream
candidates : C Language )
(c) Name the four basic types of constant in C.
(d) Differentiate between array of pointers and pointer
to an array.
(e) How is structure different from an array? Explain.
(f) How are library function different from user define
function?
(g) Write a program using macro to find the area of a
circle.

HS/XII/A.Sc.Com/CAP/OC/20/35 [ P.T.O.

( 8 )

( PART : B—DESCRIPTIVE )
( Marks : 35 )
UNIT—I
( For Science stream candidates only )

5. (a) Simplify the following logical expressions : 1+1=2
(i) XY  X Z  YZ
(ii) XY Z   XY Z W  XZ 

(b) Draw the K-map for the following Boolean function
and simplify it : 2
F ( A, B , C , D )  (0,1,5,7,9,10,11,12,13,14,15)
(c) Draw a 3-variable K-map in two different forms. 1
OR
6. (a) Point out the difference between Boolean algebra
and real number algebra. 2
(b) Convert the following POS expression in canonical
form: 1
( A  B  C )(A  D )
(c) Simplify the following expressions by K-map
method: 1+1=2
(i) Y  A B   AB   A B
(ii) Y  ( A  B   C   D )( A   B   C   D )
(A  B   C   D )
7. (a) Define Karnaugh map. Draw a single variable
K-map. 2
(b) Draw a logic gate for the following Boolean
expression: 1
Y  AB C  ABC   ABC

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( 9 )

(c) Write the SOP of the function F(A,B,C). The truth
table for F is as follows : 2

A B C F
0 0 0 1
0 0 1 0
0 1 0 0
0 1 1 1
1 0 0 0
1 0 1 0
1 1 0 1
1 1 1 0

OR

8. (a) Explain AND and OR operations with suitable
examples of logic statements. 2

(b) Simplify the logical expression

( X  Y )( X   Z )(Y  Z ) 2

(c) Explain don’t care condition. 1

( For Arts / Commerce stream candidates only )

5. (a) Write a note on classes of network address. 3

(b) List down the steps to make an image into a
hyperlink. 2
OR

6. (a) What is a Web server? How is it different from Web
pages? 2

(b) Explain the three different types of network
connectivity. 3

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( 10 )

7. (a) What is URL? List out the three parts of URL. 2
(b) Write down the steps to add image to the Web page. 3
OR
8. Explain the header fields of an e-mail message. 5

( Unit-II, Unit-III and Unit-IV :
For all Science / Arts / Commerce stream candidates )

UNIT—II
9. (a) What is a variable? How are variables appearing
within a C program declared? Explain with example.
1+1=2

(b) Name and describe the four basic data types in C. 2
OR
10. (a) How does scanf() function differ from gets() function
while accepting string from the keyboard? 1
(b) What is the difference between ‘i++’ and ‘++i’? 1
(c) Compare the use of if-else statement with the use
of ? : operator with example. 2

11. (a) What are relational operator and logical operator?
How are they used in if statement? 2
(b) Explain the difference in the syntaxes of ‘for loop’
and ‘while loop’. 2
OR
12. (a) What is the use of default keyword inside the
switch statement? Explain with example. 2
(b) What is the use of format specifier in printf() and
scanf() functions? 2

HS/XII/A.Sc.Com/CAP/OC/20/35 [ Contd.

( 11 )

UNIT—III

13. (a) Write a note on any of the two storage classes in C. 2
(b) Write a program using function name as int sum
(int x, int y) to find the sum of two numbers. 2
(c) Define pointer. 1
OR

14. (a) What are formal and actual arguments? What is the
relationship between them? 3
(b) Write a program using function as void reverse() to
reverse a number. 2

15. (a) What is a function? Explain call by value and call by
reference. 3
(b) What is the difference in the function prototype
void display() and int display()? 2
OR
16. (a) Write a program using function to swap two
numbers. 2
(b) What is recursion? 1
(c) How does an array variable differ from an ordinary
variable? How can array elements be accessed? 2

UNIT—IV

17. (a) What is the difference between #include
<filename.h> and #include “filename.h”? 2
(b) Discuss fgets (s, 30, fp). 112

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( 12 )

OR
18. (a) Write a program using structure to store the details
of students name, roll_no and age. 2
(b) Describe the work of preprocessor in C. 112

19. (a) Point out the similarities and difference on the
mode “w” and “a”. 2
(b) What is the difference between fprintf() and fwrite()
functions? 112
OR

20. (a) Summarize the preprocessor directries #include and
#define. 2
(b) What are the two operators used to access the
elements of a structure? 112

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HS/XII/A.Sc.Com/CAP/OC/20/35 20K—830