Information Technology · Class 11 Commerce
Ch 1Introduction to Computer System — Class 11 Information Technology, concept-first.
A computer is an electronic machine that accepts data, processes it according to a set of instructions, stores the data and results, and gives out useful information — quickly, accurately, and automatically. It has become the single most important tool of modern business, education, government, and daily life.
Key concepts
Hover a concept to preview it and jump to its most relevant Q&A.
Central Processing Unit
The central processing unit (CPU), a single microprocessor chip, is the brain of the computer that interprets and executes instructions and controls all other units.
Most relevant Q&A
- Which part of the computer is called the "brain of the computer"? (A) Random Access Memory (RAM) (B) Central Processing Unit (CPU) (C) Monit…Free
- Which of the following performs arithmetic and logical operations in the CPU? (A) Control Unit (B) Registers (C) Arithmetic and Logic Unit (…Free
- What is a CPU? Name and briefly explain its three main components.Free
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
What This Chapter Covers
A computer is an electronic machine that accepts data, processes it according to a set of instructions, stores the data and results, and gives out useful information — quickly, accurately, and automat…
The Computer System and Its Organisation
A computer system is the complete working combination of hardware (the physical machine you can touch) and software (the instructions that make the hardware do useful work), together with the data it…
The Central Processing Unit (CPU)
The central processing unit (CPU) is the part of the computer that actually carries out the processing — it interprets and executes instructions and controls the working of all the other units.
The Memory Unit
The memory unit is the part of the computer that stores data, instructions, and results. Without memory the CPU would have nowhere to keep the program it is running or the data it is working on.
Input Devices
An input device is any hardware used to feed data and instructions into the computer. It converts the information a human provides — letters, numbers, clicks, sounds, images — into the electronic form…
Output Devices
An output device is any hardware that gives out the results produced by the computer, converting the computer's electronic signals into a form a human can see, hear, or hold.
The Communication Bus and Ports
The different units of a computer — CPU, memory, and input/output devices — must be able to send data and signals to one another.
Types of Software
Software is a set of instructions, called a program, that tells the computer hardware what to do. Without software the hardware is just idle machinery.
More questions
14 Q+−Show 7 questionsHide questions7 questions
- Q1Which part of the computer is called the "brain of the computer"? (A) Random Access Memory (RAM) (B) Central Processing Unit (CPU) (C) Monit…Free
- Q2Which of the following performs arithmetic and logical operations in the CPU? (A) Control Unit (B) Registers (C) Arithmetic and Logic Unit (…Free
- Q3Which type of memory loses all its contents when the computer is switched off? (A) ROM (B) RAM (C) Hard disk (D) Pen driveFree
- Q4How many bits make one byte? (A) 2 bits (B) 4 bits (C) 8 bits (D) 1,024 bitsPreview
- Q5Which of the following is an input device? (A) Printer (B) Monitor (C) Scanner (D) PlotterPreview
- Q6Which part of the system bus carries the location in memory that the CPU wants to read from or write to? (A) Data bus (B) Address bus (C) Co…Preview
- Q7The operating system is an example of: (A) Application software (B) Utility software (C) System software (D) Open-source hardwarePreview
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- Q8Distinguish between hardware and software, giving two examples of each.Free
- Q9What is a CPU? Name and briefly explain its three main components.Free
- Q10Differentiate between primary memory and secondary storage.Preview
- Q11What is utility software? Give any four examples and state what each does.Preview
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- Q12Explain the different functional units of a computer with the help of a block diagram, describing how data flows through them.Free
- Q13Explain the three main types of software with suitable examples, and state what is meant by open-source software.Preview
- Q14What are input and output devices? Explain any four input devices and any four output devices, and distinguish between soft copy and hard co…Preview