In binary representation used in digital electronics and computer systems, which digit represents the OFF state?

Introduction / Context:
This question checks your understanding of the basic binary system, which is fundamental in computer science and digital electronics. Binary uses only two digits, and these digits correspond closely to physical states such as ON and OFF, or high and low voltage, in digital circuits. Knowing which digit corresponds to the OFF state is essential for interpreting logic diagrams and truth tables.

Given Data / Assumptions:
- Binary representation uses two digits: 0 and 1.- These digits are mapped to logical and physical states in digital systems.- We are asked specifically which digit represents the OFF state.

Concept / Approach:
In digital electronics and binary logic, the digit 1 generally represents the presence of a signal, a high voltage level, logical true, or ON. In contrast, the digit 0 represents the absence of a signal, a low voltage level, logical false, or OFF. This mapping is consistent across most digital systems and programming languages. The binary system is thus a two state encoding of physical ON and OFF conditions.

Step-by-Step Solution:
- Recall that binary digits are 0 and 1.- In logical terms, 1 corresponds to true or ON, and 0 corresponds to false or OFF.- In hardware, 1 generally corresponds to a higher voltage level, while 0 corresponds to a lower or zero voltage level.- Because OFF means the signal or power is not present, this aligns with the digit 0.- Therefore, in binary representation the OFF state is represented by digit 0.

Verification / Alternative check:
Look at common logic gates such as AND, OR, and NOT in digital electronics. Their truth tables always use 0 to represent the false or OFF condition and 1 for the true or ON condition. For example, in an AND gate, input 0 means the line is OFF and cannot contribute to turning the output ON. These standard conventions confirm that 0 is associated with OFF in binary systems.

Why Other Options Are Wrong:
- Option 1: This digit corresponds to ON, true, or high state in binary logic.- Options 2, 3, and 4: These digits are not even valid binary digits and are not used to represent basic ON or OFF states in binary coded systems.

Common Pitfalls:
Beginners sometimes confuse the mapping when they see diagrams where a line labelled 1 is drawn low and 0 is drawn high for stylistic reasons. The correct interpretation always follows the underlying convention: 1 is a logically active or ON state, and 0 is logically inactive or OFF. Remember that the binary system is strictly limited to digits 0 and 1, so any value outside this set cannot represent a basic binary state.

Final Answer:
In binary representation, the digit representing the OFF state is 0.