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
21
Which is the largest unit of data storage?
Answer:
Word
Among the options provided, a "word" is the largest. A bit is the smallest unit (a single 0 or 1). A byte is a group of 8 bits. A computer "word" refers to the natural unit of data used by a processor, which is typically larger than a byte and can be 16, 32, or 64 bits long depending on the computer's architecture.
22
What does ASCII provide?
Answer:
128 different characters
Standard ASCII (American Standard Code for Information Interchange) is a 7-bit character code, which means it can represent 2^7, or 128, different characters. These include uppercase and lowercase English letters, numbers, punctuation marks, and control characters. Extended ASCII uses 8 bits to represent 256 characters.
23
The number (11)₁₆ is what in decimal?
Answer:
17
(1 \* 16¹) + (1 \* 16⁰) = 16 + 1 = 17.
24
What is the result when the binary number (101)₂ is multiplied by the binary number (11)₂? Express your answer in binary form.
Answer:
(1111)₂
To calculate the product of (101)₂ and (11)₂, we can use a method similar to long multiplication in base 10: Step 1: Multiply (101)₂ by the rightmost digit of (11)₂, which is '1'. (101)₂ × 1 = (101)₂ Step 2: Multiply (101)₂ by the next digit of (11)₂, which is '1'. Shift the result one position to the left (equivalent to multiplying by 2 in binary). (101)₂ × 1 shifted left = (1010)₂ Step 3: Add the results from Step 1 and Step 2. (101)₂ + (1010)₂ ------- (1111)₂ Alternatively, we can convert the binary numbers to decimal, multiply, and then convert the product back to binary: Convert (101)₂ to decimal: (1 * 2^2) + (0 * 2^1) + (1 * 2^0) = 4 + 0 + 1 = 5₁₀ Convert (11)₂ to decimal: (1 * 2^1) + (1 * 2^0) = 2 + 1 = 3₁₀ Now, multiply the decimal numbers: 5₁₀ × 3₁₀ = 15₁₀ Finally, convert 15₁₀ back to binary: 15 ÷ 2 = 7 remainder 1 7 ÷ 2 = 3 remainder 1 3 ÷ 2 = 1 remainder 1 1 ÷ 2 = 0 remainder 1 Reading the remainders from bottom to top gives (1111)₂. Therefore, the product of (101)₂ and (11)₂ is (1111)₂.
25
How many bits are there in 8 bytes?
Answer:
64 bits
A single byte is defined as a sequence of 8 bits. To find the total number of bits in 8 bytes, you multiply the number of bytes by 8. So, 8 bytes × 8 bits/byte = 64 bits.
26
In Boolean algebra, what is the simplified output of the expression 'A OR 1'?
Answer:
1 (Logical one)
This expression demonstrates the Annulment Law (also known as the Dominance Law or OR Identity) in Boolean algebra. The OR operation returns 'true' (or 1) if at least one of its inputs is true. In the expression 'A + 1' (where '+' represents the OR operation), one of the inputs is always '1'. Therefore, regardless of whether A is '0' or '1', the result of the OR operation will always be '1'. Let's consider both possibilities for A: If A = 0, then 0 + 1 = 1. If A = 1, then 1 + 1 = 1. In both cases, the output is 1.
27
In Boolean algebra, what is the outcome when any Boolean variable 'A' is subjected to a logical AND operation with the Boolean constant '1'?
Answer:
A
This operation demonstrates the Identity Law for the Logical AND operator in Boolean algebra. When a Boolean variable 'A' (which can be either 0 or 1) is ANDed with '1', the result is always 'A' itself. Let's examine the two possible cases for 'A': 1. If A = 0: Then A · 1 = 0 · 1 = 0. In this case, the result (0) is equal to A. 2. If A = 1: Then A · 1 = 1 · 1 = 1. In this case, the result (1) is also equal to A. In both scenarios, the output of the operation A · 1 is identical to the value of A. Therefore, '1' acts as the identity element for the logical AND operation, meaning it does not alter the value of the variable it operates on.
28
The number (11)₈ is what in decimal?
Answer:
9
(1 \* 8¹) + (1 \* 8⁰) = 8 + 1 = 9.
29
Which coding system can represent up to 65,536 symbols?
Answer:
Unicode
The original 16-bit version of Unicode was designed to represent 2^16, or 65,536, unique characters. This allows it to encompass characters from most of the world's writing systems in a single character set, far exceeding the capacity of 7-bit ASCII (128) or 8-bit EBCDIC (256).
30
If you encounter a file named "install.exe", what is its most probable function?
Answer:
It is an executable file for installing a program.
The ".exe" extension signifies an executable file. A file named "install.exe" is almost certainly a program designed to install software onto a computer.