Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
In Boolean algebra, what is the simplified form of the expression A OR NOT A (A + A')?
Answer:
1
The expression A + A' represents the logical OR operation between a variable 'A' and its complement 'A'' (NOT A). According to the Complement Law in Boolean algebra, any variable ORed with its complement always results in a logical TRUE (represented by '1'). Let's verify this with all possible values for 'A': 1. If A = 0 (False): Then, A' (NOT A) = 1 (True). Substituting these into the expression: 0 + 1 = 1. 2. If A = 1 (True): Then, A' (NOT A) = 0 (False). Substituting these into the expression: 1 + 0 = 1. In both exhaustive cases, the result of the expression A + A' is 1. Therefore, the simplified Boolean expression for A + A' is 1.
2
What type of gates are AND, OR, and NOT classified as?
Answer:
Logic gate
AND, OR, and NOT are fundamental building blocks in digital electronics known as logic gates. They perform basic logical functions based on Boolean algebra and are the basis for all digital circuits, including those in a computer's CPU.
3
The number (11)₂ is what in decimal?
Answer:
3
(1 \* 2¹) + (1 \* 2⁰) = 2 + 1 = 3.
4
What type of number system has eight different symbols to represent any quantity?
Answer:
Octal
The octal number system is a base-8 system, meaning it uses eight distinct symbols to represent numbers. These symbols are the digits 0, 1, 2, 3, 4, 5, 6, and 7.
5
BCD stands for
Answer:
Binary Coded Decimal
BCD, or Binary-Coded Decimal, is a method of representing decimal numbers in binary form. In this system, each decimal digit (0-9) is encoded as a four-bit binary number, which makes it easier for digital systems to handle decimal arithmetic.
6
What does the acronym EBCDIC represent?
Answer:
Extended Binary Coded Decimal Interchange Code
EBCDIC stands for Extended Binary Coded Decimal Interchange Code. It is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems.
7
When formulating search queries on the Internet, which of the following Boolean operators are frequently employed to enhance the precision and relevance of results?
Answer:
All of the above
Boolean operators are indispensable tools for constructing effective and targeted search queries across various search engines and databases on the internet. * **AND**: This operator serves to narrow down search results. It ensures that every specified term must appear in the documents returned. For instance, a search for 'ancient Egypt AND pyramids' will only yield results that contain both 'ancient Egypt' and 'pyramids'. * **OR**: Conversely, this operator broadens the scope of search results. It retrieves documents that contain at least one of the specified terms. A search for 'jaguar OR leopard' would return pages mentioning 'jaguar', pages mentioning 'leopard', or pages mentioning both. * **NOT**: This operator (often represented by a hyphen '-' in many search engines) is used to exclude specific terms from the search results. For example, searching 'apple NOT fruit' would provide information about Apple the company or technology, while intentionally omitting results related to the apple as a produce item. While other Boolean operators like NAND and NOR exist in formal logic, AND, OR, and NOT are the most widely recognized, implemented, and essential for refining searches on general internet platforms.
8
Which of the following accurately represents the full name for the widely used character encoding system, ASCII?
Answer:
American Standard Code for Information Interchange
ASCII, an acronym for 'American Standard Code for Information Interchange,' is a critical character encoding standard. It assigns unique numerical values to characters, including letters (uppercase and lowercase), numbers, punctuation marks, and control codes. This standardization allows computers and other devices to uniformly represent and exchange text-based information. For example, the ASCII value for the uppercase letter 'A' is 65, and for the lowercase 'a' is 97. While more comprehensive encoding systems like Unicode have emerged, ASCII remains fundamental to computing history and forms the base for many modern character sets.
9
What is the maximum number of unique symbols that can be represented in an 8-bit ASCII code?
Answer:
256 characters
The 8-bit ASCII code uses 8 binary digits to represent each character, resulting in a total of 2^8 or 256 possible unique symbols.
10
Which of the following accurately represents the full meaning of the acronym 'ASCII'?
Answer:
American Standard Code for Information Interchange
ASCII stands for 'American Standard Code for Information Interchange'. It is a character encoding standard that was developed in the 1960s. Its primary purpose is to provide a standardized way for computers to represent text, allowing different computer systems and devices to communicate and exchange information (like text documents) consistently. Each character (letters, numbers, punctuation, control characters) is assigned a unique 7-bit binary code, which means there are 128 possible characters in the standard ASCII set.