Computer Science Test - 27

The most reliable way to make sure you are safe is to open an email attachment or click on a link is to scan it with anti-virus software.

'tup1[2]=20' will make an error.

Here, the first option 'print(tup1[2])' will display the value at the position.

Therefore, print(tup1[2])=25. The starting position is 0.

print(min(tup1)) will display the minimum value in that tuple.

Here, print(min(tup1))=10

print(len(tup1)) will give output as the tuple length.

print(len(tup1)) = 4

But, tup1[2]=20 means assigning a new value to the position.

In tuples, values are constant.

So, tup1[2]=20 will result in an error.

Statement (A) is correct: A stack follows the Last-In, First-Out (LIFO) principle, meaning the last element added is the first to be removed.

Statement (B) is correct: The PUSH operation adds an element to the top of the stack.

Statement (C) is incorrect: The POP operation removes an element from the top, not the bottom, of the stack.

Statement (D) is correct: A stack can be implemented using Python lists, where append() is used for PUSH, and pop() is used for POP.

Thus, the correct answer is (1) (A), (B), and (D) only.

There are some codes to handle a file in a programming language.

myfile=open('student. txt', 'w') is the mode that allows opening a file in write mode.

myfile=open('student.txt', 'r') is the mode that open file in only read mode.

myfile= open ('student.txt') is also allowed to open in reading mode.

The pickle module implements binary protocols for serializing and de-serializing a Python object structure.

Here, Check will be treated as a string, not a tuple, as there is no comma after the element.

The correct option is B

A → III, B → I, C → IV, D → II

Concept:

Match the following:

A: Modem → III: The device used for conversion between electric signals and digital bits.

B: Ethernet card → I: A network adapter is used to set up a wired network.

C: Repeater → IV: Regenerate the signals.

D: Switch → II: Connect multiple computers.

The correct answer is option C.

Concept:

Queues:

The queue is an abstract data structure, somewhat similar to Stacks.

Unlike stacks, a queue is open at both ends. One end is always used to insert data (en queue) and the other is used to remove data (de queue). Queue follows the First-In-First-Out methodology, i.e., the data item stored first will be accessed first.

Queue follows the principle of First In First Out (FIFO) and Last In Last Out (LILO)

maxsize:

The maximum number of items in the queue. 

put(item): 

Add something to the queue. Wait until a free spot becomes available if the queue is filled before adding the item. 

qsize(): 

Return the number of items in the queue.

full():

If there are maxsize items in the queue, return True. 

get():

A queue item can be removed and returned. Wait until an item is available if the queue is empty.

empty():

Return True if the queue is empty, False otherwise. Here queue is not empty because the still elements are there in the queue. Example:

Explanation:

from queue import Queue

q=Queue(maxsize=10)

q.put('A')

q.put('AA')

q.put('AAA')

print(q.qsize())

print(q.full())

print(q.get())

print(q.empty())

Hence the correct answer is empty().

(A) DDL → (I) Used to define and modify database structures such as tables, indexes, and constraints (CREATE, ALTER, DROP).

(B) DML → (III) Includes commands like INSERT, UPDATE, and DELETE, modifying database records.

(C) DQL → (II) Used to retrieve data using the SELECT statement.

(D) DCL → (IV) Grants and revokes user access permissions using commands like GRANT and REVOKE.