Computer Science - IT MCQs
Topic Notes: Computer Science - IT
<p>MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.</p>
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
531
The number system we use for counting in our daily lives is:
Answer:
Decimal
The decimal (base-10) system is the standard system for denoting integers and non-integer numbers in everyday life.
532
What is the decimal equivalent of the hexadecimal number (11)₁₆?
Answer:
17
To convert a hexadecimal number to its decimal equivalent, each digit is multiplied by a power of 16, corresponding to its position, and the results are summed.
For the hexadecimal number (11)₁₆:
- The rightmost digit '1' is in the 16⁰ (units) place.
- The leftmost digit '1' is in the 16¹ (sixteens) place.
Calculation:
(1 * 16¹) + (1 * 16⁰)
= (1 * 16) + (1 * 1)
= 16 + 1
= 17
Therefore, the decimal equivalent of (11)₁₆ is 17.
533
Which of the following is a key characteristic of a positional number system?
Answer:
The value of a digit depends on its position within the number
In a positional system, the position of a digit determines its value. For example, in the number 555, each '5' has a different value (500, 50, and 5) because of its position.
534
In hexadecimal, what decimal value does the letter 'A' represent?
Answer:
10
In the hexadecimal system, the symbols A, B, C, D, E, and F are used to represent the decimal values 10, 11, 12, 13, 14, and 15, respectively.
535
The number (19)₁₀ is a value in which number system?
Answer:
Decimal
The subscript '10' explicitly denotes that this is a base-10 or decimal number.
536
Performing subtraction using the two's complement method involves:
Answer:
Finding the two's complement of the subtrahend and adding it to the minuend
The operation A - B is equivalent to A + (-B). The two's complement is used to find the representation of -B, allowing the subtraction to be carried out by an adder circuit.
537
What is the decimal equivalent of the binary number (1011)₂?
Answer:
11
(1 \* 2³) + (0 \* 2²) + (1 \* 2¹) + (1 \* 2⁰) = 8 + 0 + 2 + 1 = 11.
538
How does UTF-8 handle code points larger than 127 (the ASCII range)?
Answer:
It uses a sequence of two to four bytes, where the first byte indicates how many bytes are in the sequence
This multi-byte scheme is the core of how UTF-8 works. Special bit patterns in the first byte tell the parser how many subsequent bytes are part of the same character.
539
How is the decimal number 13 represented in binary?
Answer:
(1101)₂
13 can be broken down into powers of 2: 8 + 4 + 0 + 1, which corresponds to (1 \* 2³) + (1 \* 2²) + (0 \* 2¹) + (1 \* 2⁰), or 1101 in binary.
540
The two's complement representation is commonly used to:
Answer:
Represent negative integers
Two's complement is a mathematical operation on binary numbers that allows subtraction to be performed using addition, and it provides a standard way to represent negative numbers in computer systems.