Computer Science · Sample Paper 3

General instructions

Section A · Objective

1. Question 11 mark

   Which of these is a secondary storage device?

   1. A.RAM
   2. B.cache
   3. C.hard disk
   4. D.register
2. Question 21 mark

   Software that translates and executes a program line by line is an

   1. A.compiler
   2. B.interpreter
   3. C.assembler
   4. D.linker
3. Question 31 mark

   $(101010{)}_2$ in decimal is

   1. A.40
   2. B.42
   3. C.44
   4. D.38
4. Question 41 mark

   $(57{)}_{10}$ in octal is

   1. A.71
   2. B.57
   3. C.61
   4. D.72
5. Question 51 mark

   UTF-8 is an encoding of

   1. A.ASCII only
   2. B.Unicode
   3. C.ISCII
   4. D.BCD
6. Question 61 mark

   Which technology lets computers learn from data without being explicitly programmed?

   1. A.machine learning
   2. B.blockchain
   3. C.cloud storage
   4. D.VR
7. Question 71 mark

   A step-by-step finite procedure to solve a problem is an

   1. A.algorithm
   2. B.program only
   3. C.flowchart only
   4. D.error
8. Question 81 mark

   What is the output of print(15 % 4)?

   1. A.3
   2. B.3.75
   3. C.4
   4. D.1
9. Question 91 mark

   Which of these is a keyword in Python?

   1. A.total
   2. B.elif
   3. C.value
   4. D.data
10. Question 101 mark

    What is the output of print(bool(''))?

    1. A.True
    2. B.False
    3. C.None
    4. D.error
11. Question 111 mark

    What does this print?

    i = 1
    while i < 5:
        i += 2
    print(i)
    

    1. A.3
    2. B.5
    3. C.4
    4. D.7
12. Question 121 mark

    Which statement does nothing and is used as a placeholder?

    1. A.break
    2. B.continue
    3. C.pass
    4. D.return
13. Question 131 mark

    A small anonymous (unnamed) function is created using the keyword

    1. A.def
    2. B.lambda
    3. C.class
    4. D.import
14. Question 141 mark

    What is len('Hello World')?

    1. A.10
    2. B.11
    3. C.12
    4. D.9
15. Question 151 mark

    What does 'python'.capitalize() return?

    1. A.'PYTHON'
    2. B.'Python'
    3. C.'python'
    4. D.'pYTHON'
16. Question 161 mark

    L = [5, 3, 8]. What does sorted(L) return?

    1. A.[8, 5, 3]
    2. B.[3, 5, 8]
    3. C.None
    4. D.[5, 3, 8]
17. Question 171 mark

    L = [1, 2, 3]; M = L; M.append(4). What is L?

    1. A.[1, 2, 3]
    2. B.[1, 2, 3, 4]
    3. C.[4]
    4. D.error
18. Question 181 mark

    Which of these creates an empty dictionary?

    1. A.[]
    2. B.()
    3. C.{}
    4. D.set()
19. Question 191 mark

    Using someone's work without giving credit is

    1. A.copyright
    2. B.plagiarism
    3. C.licensing
    4. D.open source
20. Question 201 mark

    Assertion (A): s = 'abc'; s.upper() changes s to 'ABC'.

    Reason (R): String methods return new strings without modifying the original.

    1. A.Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.
    2. B.Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.
    3. C.Assertion (A) is true, but Reason (R) is false.
    4. D.Assertion (A) is false, but Reason (R) is true.
21. Question 211 mark

    Assertion (A): A function can return more than one value in Python.

    Reason (R): Multiple values separated by commas are returned as a tuple.

    1. A.Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.
    2. B.Both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.
    3. C.Assertion (A) is true, but Reason (R) is false.
    4. D.Assertion (A) is false, but Reason (R) is true.

Section B · Very short answer

1. Question 222 marks

   Differentiate between a compiler and an interpreter.

2. Question 232 marks

   Convert $(1101.101{)}_2$ to decimal.

3. Question 242 marks

   Write the output:

   x = 10
   y = 3
   print(x // y, x % y, x ** 2)
   

4. OR

   Question 242 marks

   Differentiate between mutable and immutable data types with one example each.

5. Question 252 marks

   Rewrite the following using a for loop:

   i = 10
   while i > 0:
       print(i)
       i -= 2
   

6. Question 262 marks

   Write the output:

   s = 'banana'
   print(s.count('a'), s.replace('a', 'o'))
   

7. Question 272 marks

   Write the output:

   t = (10, 20, 30, 40)
   print(t[1:3])
   print(max(t) - min(t))
   

8. Question 282 marks

   What is a digital footprint? Give two ways to keep it safe.

Section C · Short answer

1. Question 293 marks

   Write a Python program to print the Fibonacci series up to n terms.

2. OR

   Question 293 marks

   Write a Python program to find the factorial of a number using a while loop.

3. Question 303 marks

   Write a Python program that reads a list of numbers and creates a new list containing only the numbers greater than the average.

4. Question 313 marks

   Write the output:

   def change(a, b=5):
       a = a + b
       return a
   
   x = 3
   print(change(x))
   print(change(x, 10))
   print(x)
   

Section D · Long answer

1. Question 324 marks

   Write a function is_perfect(n) that returns True if n is a perfect number (sum of proper divisors equals n). Use it to print all perfect numbers below 1000.

2. Question 334 marks

   Write a program that reads a string and prints it with the case of each letter swapped and the words reversed in order (e.g. 'Hello World' → 'wORLD hELLO').

3. OR

   Question 334 marks

   Write a program to check whether a sentence is a pangram (contains every letter of the alphabet at least once).

4. Question 344 marks

   Write a program to create a dictionary of n countries and their capitals entered by the user, then display the countries whose capital names begin with a vowel.

5. Question 354 marks

   Explain (i) open-source software (ii) copyright (iii) licence (iv) Creative Commons, with an example each.

Section E · Long answer

1. Question 365 marks

   Write a menu-driven program to manage a list of student names: (1) add a name, (2) delete a name if present, (3) search for a name, (4) display all names in sorted order, (5) exit.

2. OR

   Question 365 marks

   Write a program that reads a paragraph and builds a dictionary of word frequencies (case-insensitive), then prints the three most frequent words.

3. Question 375 marks

   Explain (i) cloud computing and its service models (ii) Internet of Things (iii) grid computing, with one application each.