In binary code, the number 7 is written as?

Appeared in: UPRVUNL - 2021

Explanation

The binary number system is a base-2 system, using only the digits 0 and 1.
Each position in a binary number represents a power of 2, starting from the right: 2⁰ (1), 2¹ (2), 2² (4), and so on.
The decimal number 7 is the sum of the powers of 2: 4 + 2 + 1.
This corresponds to 1×2² + 1×2¹ + 1×2⁰, which is written as 111 in binary.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Decimal to Binary Conversion as background academic context rather than a clinical decision trigger.
This question tests general knowledge and computer literacy, which is a component of some nursing entrance examinations.
Understanding binary is foundational to how digital devices, including many modern medical instruments, store and process information.
What if the question asked for the binary representation of the number 8? The place values are ..., 8, 4, 2, 1. Since 8 is a power of 2 (2³), its binary representation would be 1000.

How to Approach the Question

Identify the question type: This is a factual recall question from the subject of computer awareness/general knowledge.
Recall the principles of the binary number system (base-2).
Understand that each digit position represents a power of 2 (..., 16, 8, 4, 2, 1).
To convert a decimal number (like 7) to binary, find the largest power of 2 that is less than or equal to the number. For 7, this is 4 (2²). Place a '1' in that position.
Subtract this value from the original number (7 - 4 = 3) and repeat the process with the remainder until it is zero.
The next largest power of 2 for the remainder 3 is 2 (2¹). Place a '1' in that position. The new remainder is 3 - 2 = 1.

Concept Tested & Keywords

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