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
231
A "carry" in binary addition occurs when:
Answer:
The sum in a column is 2 or greater
A carry is generated when the result of adding the digits in a single column cannot be represented by a single digit in that number system. In binary, any sum greater than 1 (i.e., 2 or 3) will produce a carry.
232
What is the result of the binary multiplication (10)₂ \* (10)₂?
Answer:
(100)₂
Multiplying by (10)₂ is the same as shifting left by one position. So 10 shifted left becomes 100. (In decimal: 2 \* 2 = 4).
233
What is the sum of the binary numbers (101)₂ and (010)₂?
Answer:
(111)₂
Adding column by column from right to left: 1+0=1, 0+1=1, 1+0=1. The result is 111.
234
Using 4-bit two's complement, what is the representation of -3?
Answer:
1101
Start with positive 3: (0011)₂. Invert the bits: (1100)₂. Add 1: 1100 + 1 = (1101)₂.
235
1 TB is equal to how many GB?
Answer:
1024 GB
In the standard hierarchy of data storage units, one Terabyte (TB) is equal to 1024 Gigabytes (GB). [cite: 436] [cite_start]This follows the pattern where each successive unit is 1024 times larger than the previous one (e.g., 1 GB = 1024 MB). [cite: 437]
236
What is the decimal equivalent of the binary number (11)₂?
Answer:
3
To convert a binary number to its decimal equivalent, we multiply each digit by a power of 2, starting from the rightmost digit with 2^0, and increasing the power for each subsequent digit to the left. Then, we sum the results.
For the binary number (11)₂:
* The rightmost digit is 1, which is in the 2^0 (or units) place. So, 1 * 2^0 = 1 * 1 = 1.
* The next digit to the left is 1, which is in the 2^1 (or twos) place. So, 1 * 2^1 = 1 * 2 = 2.
Now, we sum these products: 1 + 2 = 3.
Therefore, the decimal equivalent of (11)₂ is 3.
237
How can you create a NOT gate using only a 2-input NAND gate?
Answer:
Connect both inputs of the NAND gate together
If you tie the inputs A and B together, then the input is A AND A, which is just A. The NAND gate then inverts this, producing NOT A.
238
What is a "code point" in the context of Unicode?
Answer:
A unique number assigned to a single character or symbol in the Unicode standard
Every character in the Unicode standard is assigned a unique numerical value, called a code point, written in the format U+XXXX (where XXXX is a hexadecimal number).
239
In Boolean algebra, what is the outcome when any variable 'A' is subjected to a logical AND operation with the constant '1'?
Answer:
A
This question tests understanding of fundamental Boolean algebra identities, specifically the Identity Law for the AND operation. When a Boolean variable 'A' (which can be either 0 or 1) is ANDed with '1', the result always mirrors the value of 'A'.
Let's examine the two possible cases for 'A':
1. If A = 0: Then A ⋅ 1 = 0 ⋅ 1 = 0. In this case, the result is A.
2. If A = 1: Then A ⋅ 1 = 1 ⋅ 1 = 1. In this case, the result is A.
In both scenarios, the output of the operation 'A ⋅ 1' is equivalent to 'A' itself. Therefore, 'A' is the correct answer. This law is crucial for simplifying Boolean expressions and understanding digital logic circuits.
240
Why is it a security risk to grant "write" permission to all users for a system folder?
Answer:
Any user could potentially delete or modify critical system files, causing instability or a crash.
System files should be protected with restrictive permissions to maintain the integrity of the operating system.