NCERT Class 12 Computer Science Computer Science: Chapter 6 — Searching
This chapter introduces the fundamental concept of searching in computer science. It explains that searching is the process of locating a specific element within a collection of data. The chapter details the Linear Search algorithm, also known as sequential or serial search. This method involves comparing the target key with each element in the list one by one until a match is found or the entire list is traversed. It is suitable for small, unordered collections. The chapter also briefly mentions other search techniques like Binary Search and Hashing, highlighting their importance for efficient data retrieval in computer programs. Understanding these searching techniques is crucial for designing effective algorithms.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Computer Science |
| Book | Computer Science |
| Chapter | Chapter 6 — Searching |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 2 minutes |
| Word count | 336 |
Learning outcomes
- Understand the importance of searching in computer science.
- Explain the concept of searching and its role in data retrieval.
- Describe the Linear Search algorithm step-by-step.
- Analyze the efficiency of Linear Search for different data collections.
- Identify scenarios where Linear Search is applicable.
Vocabulary
| Word | Meaning |
|---|---|
| Searching | The process of locating a particular element in a collection of elements. |
| Key | The item to be searched for in a list or collection. |
| Linear Search | A simple search algorithm that checks each element of a list sequentially until a match is found or the list is exhausted. |
| Sequential Search | Another name for Linear Search, emphasizing the item-by-item comparison in order. |
| Serial Search | Synonym for Linear Search, referring to the sequential checking of elements. |
| Collection of elements | A group or list of data items. |
| Element | A single item within a collection or list. |
| Algorithm | A step-by-step procedure or set of rules to be followed in calculations or other problem-solving operations. |
| Index | A numerical position of an element in a list, usually starting from 0. |
| Traversed | Visited or processed each element in a list or data structure. |
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Practice questions
- What is the primary goal of searching in computer science? Answer: The primary goal of searching is to locate a particular element within a collection of elements and determine if it is present.
- Describe the basic principle of Linear Search. Answer: Linear Search compares the target key with each element in the list one by one, starting from the first element, until a match is found or the end of the list is reached.
- When is Linear Search considered most useful? Answer: Linear Search is most useful for collections of items that are small in size and are unordered.
- What does it mean for a search to be 'unsuccessful' in Linear Search? Answer: A search is unsuccessful when the key element is not found after comparing it with every element in the list.
Practice MCQs
Q1. Which of the following is the simplest search method?
Explanation: Linear Search is described as the most fundamental and simplest search method in the chapter.
Q2. Linear Search is also known as:
Explanation: The chapter states that Linear Search is also called sequential search or serial search due to its item-by-item comparison.
Q3. In Linear Search, if the key is the last element of the list, how many comparisons are made (assuming a list of n elements)?
Explanation: In the worst-case scenario, Linear Search needs to compare the key with all 'n' elements if it's the last element or not present.
Q4. Which type of data collection is Linear Search best suited for?
Explanation: The chapter explicitly mentions that Linear Search is useful for collections of items that are small in size and are unordered.
Q5. What does the 'index' variable typically represent in the Linear Search algorithm?
Explanation: The 'index' variable in the provided algorithm (Algorithm 6.1) is used to track the current position being examined in the numList.
Frequently asked questions
What is the main purpose of searching in computer science?
The main purpose of searching is to find a specific piece of data (an element) within a larger set of data (a collection or list).
What is Linear Search?
Linear Search is a basic algorithm that checks each element in a list sequentially until the desired element (key) is found or the list ends.
What are the other names for Linear Search?
Linear Search is also known as Sequential Search or Serial Search.
When is Linear Search a suitable method?
Linear Search is suitable for small lists or when the data is not sorted, as it doesn't require any pre-ordering of elements.
What happens if the element is not found using Linear Search?
If the element is not found after checking all items in the list, the search is declared unsuccessful.
What is the role of the 'index' in the Linear Search algorithm?
The 'index' keeps track of the current position of the element being examined in the list, starting from the beginning.
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NCERT Class 12 Computer Science — Computer Science — Chapter 6 — Searching. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.