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
111
To convert a decimal number to binary, one can use the method of:
Answer:
Repeated division by 2
The standard method is to repeatedly divide the decimal number by 2 and record the remainders. The binary number is the sequence of remainders read from bottom to top.
112
The first 128 code points of Unicode are identical to:
Answer:
Standard ASCII
To ensure easy transition and backward compatibility, the designers of Unicode made the first 128 characters (U+0000 to U+007F) a direct mapping of the 7-bit ASCII standard.
113
In Boolean algebra, what is the simplified output of the expression 'A OR 1' (A + 1)?
Answer:
1 (Logical True)
This expression demonstrates one of the fundamental properties of Boolean algebra, specifically the Annulment Law for the OR operation (also known as the Identity Law for OR when ORing with 1, or sometimes a form of dominance law). The OR operator returns 'true' (1) if at least one of its inputs is 'true' (1). In the expression 'A + 1', one of the inputs to the OR operation is always 1. Therefore, regardless of whether the variable 'A' is 0 or 1, the result of the OR operation will always be 1.
Let's verify:
If A = 0, then 0 + 1 = 1.
If A = 1, then 1 + 1 = 1.
Hence, the simplified output of (A + 1) is always 1.
114
In the decimal number 734, what is the weight of the digit 3?
Answer:
10¹
The digit 4 is in the 10⁰ (ones) place, the digit 3 is in the 10¹ (tens) place, and the digit 7 is in the 10² (hundreds) place. The weight is the power of the base associated with the position.
115
What is a binary overflow?
Answer:
When the result of an arithmetic operation is too large to fit in the number of bits available
For example, if you are using 8 bits and you add two numbers whose sum is greater than 255, an overflow occurs because the result cannot be correctly represented with only 8 bits.
116
What does the ".." notation typically represent in a command-line interface?
Answer:
The parent directory
The double-dot `..` is a standard shortcut to refer to the directory one level up in the hierarchy.
117
[cite_start]Which coding system can represent up to 65,536 symbols? [cite: 467]
Answer:
Unicode
The original 16-bit version of Unicode was designed to represent 2^16, or 65,536, unique characters. [cite: 468] [cite_start]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). [cite: 469]
118
Why might you be unable to delete a file that is currently open in an application?
Answer:
The file is locked by the operating system to prevent changes while it's in use.
To prevent data corruption, operating systems often lock files that are being accessed by a program.
119
Which gate produces a high output (1) only when its two inputs are different?
Answer:
XOR
XOR stands for "Exclusive OR". The output is true (1) if one input is true and the other is false, but not if both are true or both are false.
120
The term MSB stands for:
Answer:
Most Significant Bit
The Most Significant Bit (MSB) is the bit in a binary number that has the greatest value (the leftmost bit in a standard representation).