Class 11 CS - code. caffeine. chaos.

📒✨ CHAPTER 2 - NUMBER SYSTEM: QnAs and HOTs ✨📒

QnAs:-💡 Q1. What is a number system?

A:
A number system is a system of representing numbers using a set of symbols or digits.
There are different number systems like binary, decimal, octal, and hexadecimal, each with its own base.

💡 Q2. What is the base or radix of a number system?

A:
The base (or radix) is the number of unique digits or symbols used to represent numbers in that system.
E.g., Binary has base 2 (digits 0 and 1), Decimal has base 10 (digits 0 to 9).

💡 Q3. List the types of number systems used in computers.

A:

Decimal (Base 10)

Binary (Base 2)

Octal (Base 8)

Hexadecimal (Base 16)

💡 Q4. Why is binary number system used in computers?

A:
Because computers understand only two voltage states:
🔌 ON (1) and 🔌 OFF (0).
Binary uses just 0 and 1, so it matches perfectly with how computers operate. Easy peasy ⚡🖥️

💡 Q5. What are bits, bytes, and nibbles?

A:

Bit = 1 binary digit (0 or 1)

Nibble = 4 bits

Byte = 8 bits

💡 Q6. What is the range of digits in hexadecimal number system?

A:
Hexadecimal uses:

Digits 0 to 9

Letters A to F (where A = 10, B = 11, ..., F = 15)

💡 Q7. How many symbols are used in:

(a) Binary

(b) Octal

(c) Decimal

(d) Hexadecimal?

A:

Binary → 2 (0, 1)

Octal → 8 (0 to 7)

Decimal → 10 (0 to 9)

Hexadecimal → 16 (0 to 9, A to F)

💡 Q8. What is positional number system?

A:
In a positional number system, the value of a digit depends on:

The digit itself

Its position in the number

The base of the number system

E.g., In 245 →
2 is in 100s place = 2 × 10² = 200
4 is in 10s place = 4 × 10¹ = 40
5 is in 1s place = 5 × 10⁰ = 5
→ So total = 200 + 40 + 5 = 245

💡 Q9. How is binary number converted to decimal?

A:
Multiply each bit with 2 raised to its position, starting from right (0 index), and add them all.