RBSE Solutions Class 7 Science Chapter 13 Computer

Question 1. Which device is not an output device.
(a) Monitor
(b) Printer
(c) Key board
(d) Plotter
Answer: (c) Key board
In simple words: An output device shows us information, like a monitor or printer. A keyboard is an input device, meaning it helps us put information into the computer, not get it out.

🎯 Exam Tip: Remember the difference: input devices (like keyboard, mouse) send information to the computer, while output devices (like monitor, printer) show information from the computer.

Question 2. The part of central processing unit is:
(a) Memory
(b) A.L.U
(c) Control Unit
(d) All of the above
Answer: (d) All of the above
In simple words: The Central Processing Unit, or CPU, has several important parts that work together. These include the Memory, the Arithmetic Logic Unit (ALU), and the Control Unit, all of which are essential for the computer to function.

🎯 Exam Tip: List the three main components of the CPU clearly: Memory, ALU, and Control Unit. Explaining their individual roles briefly can earn extra marks.

Question 3. Input device is :
(a)
(b) Mouse
(c) Scanner
(d) All of the above
Answer: (d) All of the above
In simple words: Input devices are how we give information to a computer. A mouse lets us click and move things, and a scanner turns pictures or documents into digital files. These are all ways to put data in.

🎯 Exam Tip: When an "All of the above" option is present for input devices, ensure you can identify at least two valid input devices from the given options before choosing it.

Question. Fill in the blanks :
1. All the actions of computer are controlled by ................unit.
2. To check the examination answer books, .device is used.
3. Monitor, printer, speaker and plotter are..............device.
4. .printer speed is measured in CPS.
Answer:
1. Information
2. Key board
3. MICR
4. OCR
In simple words: The first blank should be "Control Unit" for computer actions, the second "OMR" for checking answer books, the third "output" for monitor/printer/speaker/plotter, and the fourth "Laser" for printer speed in CPS. These are specific computer terms.

🎯 Exam Tip: For fill-in-the-blanks, always consider the context of the sentence to choose the most appropriate term from computer basics.

Short Answer Type Questions

Question 1. Write names of input devices.
Answer:
1. Keyboard
2. Mouse
3. Magnetic ink character recognition (MICR)
4. Optical character recognition (OCR)
5. Optical mark reading (OMR)
6. Scanner
7. Touch screen
8. Microphone
9. Web camera.
Input devices help us send information and commands into the computer.
In simple words: Some common input devices are the keyboard, mouse, scanner, microphone, and webcam. These tools let us put information into the computer.

🎯 Exam Tip: When listing input devices, try to include a variety, like those for text (keyboard), movement (mouse), images (scanner), and sound/video (microphone, webcam).

Question 2. What is the difference between CRT and LCD monitor?
Answer:
**CRT Monitor:** This type of monitor uses a cathode ray tube. CRT monitors are typically larger in size and take up more space on a desk. They are also heavy and use more electricity. Because of these reasons, they are not used as much today.
**LCD Monitor:** An LCD monitor uses Liquid Crystal Display technology. These monitors are thin, take up less space, are lighter in weight, and use less electricity. This makes them a more popular choice nowadays.
In simple words: CRT monitors are old, big, heavy, and use a lot of power. LCD monitors are new, thin, light, and save electricity.

🎯 Exam Tip: When comparing items, use a clear point-by-point format or separate paragraphs for each item, highlighting differences in size, weight, technology, and power consumption.

Question 3. If you want to purchase a printer which one will be your choice and why?
Answer: I would choose to buy a laser printer. Laser printers are known for producing high-quality printouts very quickly. The printed pages from a laser printer have excellent quality and look professional. This makes them a good choice for fast and clear printing.
In simple words: I would pick a laser printer. It prints really fast and the printouts look very good.

🎯 Exam Tip: When asked for a choice and a reason, clearly state your choice first, then provide two or three distinct benefits or advantages to support it.

Question 4. Define computer on the basis of their functions.
Answer: A computer is an electronic device that processes raw data into meaningful information. It performs functions like taking input, processing it, storing results, and producing output. This helps in solving problems and managing data.
In simple words: A computer takes information we give it, works on it, saves it, and then shows us the final useful result.

🎯 Exam Tip: When defining a computer, mention its core functions: input, processing, storage, and output, as these are fundamental to its operation.

Question 1. What are the characteristics of computer. Explain the same.
Answer: A computer has several important characteristics:
1. **Storage Capacity:** Computers can store a huge amount of data, measured in bytes. They can hold all kinds of information, like text, pictures, and videos, for a long time.
2. **Accuracy:** Computers almost never make mistakes because they work based on the rule "garbage in, garbage out." This means if you give it correct information, it will give you correct results.
3. **Speed:** Computers can complete very complex calculations and tasks extremely fast, much quicker than a human.
4. **Automation:** Once a computer program is started, the computer can follow the given directions and work by itself without needing constant human help.
5. **Diligence:** A computer is an electronic device that can work continuously for many hours without getting tired or losing its efficiency.
6. **Widespread Utility:** Computers are used more and more every day. They are useful in many areas of life, such as banking, education, and printing.
In simple words: Computers are good at many things: they can store lots of data, they are very accurate, they work fast, they can do tasks automatically, they don't get tired, and they are used everywhere.

🎯 Exam Tip: When explaining characteristics, list each one clearly with a bold heading, and then provide a short, simple explanation for how the computer exhibits that trait.

Question 2. Into how can be divided?
Answer: The keys on a keyboard can be divided into 3 main parts:
(1) **Alphanumeric keys:** This section includes alphabet letters (A-Z), numbers (0-9), and special symbols like space bar, < , > , ` , * , # , @ , $ , % , ^ , & , ( , ) , / , ? , [ , ] , { , } . It also has special function keys such as Shift, Enter, Back-space, Tab, Ctrl, Esc, and Alt.
(2) **Numeric keys:** This part contains number keys from 0-9. It also has other keys like Num lock, /, *, -, Home, Page Up, Page Down, Insert, and Enter keys, often arranged like a calculator.
(3) **Function keys:** These keys are located at the top of the keyboard. There are 12 function keys, labeled F1 to F12. Each of these keys performs a different specific function depending on the program being used.
In simple words: Keyboard keys are sorted into three groups: letters and numbers with symbols, a separate number pad, and special function keys like F1 to F12.

🎯 Exam Tip: Remember the three main categories of keyboard keys: Alphanumeric, Numeric, and Function keys. Being able to name a few keys from each category is helpful.

Other Important Questions

Question 2. What is used to print big pictures or maps on paper.
(a) Plotter
(b) Dot Matrix Printer
(c) Laser Printer
(d) Ink Jet Printer
Answer: (a) Plotter
In simple words: A plotter is a special kind of printer that draws large images, like blueprints or maps, using pens or other drawing tools. It's built for very big and detailed graphics.

🎯 Exam Tip: Distinguish between regular printers (for text and smaller images) and plotters, which are specifically designed for large-format, high-precision graphics.

Question 3. Speed of which is measured in DPI?
(a) Laser Printer
(b) Ink Jet printer
(c) Dot Matrix Printer
Answer: (a) Laser Printer
In simple words: The speed of a laser printer is often measured in DPI, which stands for "dots per inch." This shows how detailed the printing is and how fast it can create those detailed images.

🎯 Exam Tip: DPI (dots per inch) usually refers to print resolution or scanner resolution, not directly "speed." However, in the context of printer capabilities, higher DPI often correlates with higher quality, which can be linked to the printer's performance. Focus on it as a measure of print quality/density.

Question 4. Which of the following is not a quality of computer?
(a) Storage
(b) Accuracy
(c) Automation
(d) Inactivity
Answer: (d) Inactivity
In simple words: Computers are known for their ability to store information, be accurate, and work automatically. Inactivity is the opposite of how computers are expected to perform; they are usually active and perform tasks.

🎯 Exam Tip: When asked to identify what is *not* a quality, look for the option that describes a negative trait or the absence of a positive one.

Question. Fill in the blanks
1. Unit of computer is used to get useful ................ from the data feeded in it.
2. With the help of ................ , majority of data and instructions are given to the computer.
3. With the help of ................ , cheques are checked in banks.
4. With the help of ................ , bills are made in large quantities.
Answer:
1. Information
2. Key board
3. MICR
4. OCR
In simple words: Computers turn data into useful information. We use a keyboard to give computers most of their data. Banks use MICR to read cheques. OCR helps to quickly read and process many bills.

🎯 Exam Tip: Understanding the function of each input device and processing unit is key to filling in these types of blanks correctly.

Very Short Answer Type Questions

Question 1. Define a computer.
Answer: A computer is a device that takes raw data and changes it into meaningful information. This process makes the data useful for users. Computers are essential tools for processing and presenting information effectively.
In simple words: A computer is a machine that takes raw facts and turns them into useful information.

🎯 Exam Tip: A good definition of a computer should highlight its ability to transform raw data into valuable information, emphasizing the input-process-output cycle.

Question 2. Name the parts of computer.
Answer:
1. Input Unit
2. Central Processing Unit
3. Output Unit.
These three main parts work together to make a computer function correctly.
In simple words: The main parts of a computer are the Input Unit (where you put information in), the Central Processing Unit (where the computer thinks), and the Output Unit (where you see the results).

🎯 Exam Tip: The fundamental architecture of a computer involves these three units. Mentioning them concisely is sufficient for a very short answer.

Question 3. What is the function of A.L.U?
Answer: The A.L.U. (Arithmetic and Logical Unit) is responsible for performing all arithmetic operations, such as addition, subtraction, multiplication, and division. It also handles logical operations, which involve comparing data. This unit is vital for all calculations a computer does.
In simple words: The ALU does all the math (like adding and subtracting) and makes decisions (like checking if one number is bigger than another) inside the computer.

🎯 Exam Tip: Clearly state that ALU performs *both* arithmetic (math calculations) and logical (comparisons, decision-making) operations. This covers its complete function.

Question 5. What is the function of scanner?
Answer: A scanner is used to convert documents or pictures from physical paper into digital files that can be stored in a computer's memory. Its operation is quite similar to a photocopier (xerox machine), as it can also help in creating duplicate digital copies of any document. This digitizing ability is very useful for archiving and sharing.
In simple words: A scanner turns paper documents or photos into digital files that a computer can save. It works much like a photocopy machine to make digital copies.

🎯 Exam Tip: Emphasize the core function of a scanner: converting hard copy (physical) into soft copy (digital) for storage and use on a computer.

Question 6. What is the function of touch screen?
Answer: A touch screen serves as an alternative to a keyboard, allowing users to give instructions to a computer by directly touching specific areas on the monitor's screen. This makes interaction with the device more intuitive and direct. It is a very user-friendly input method.
In simple words: A touch screen lets you control a computer by simply touching the monitor with your finger, instead of using a keyboard or mouse.

🎯 Exam Tip: For touch screens, mention its role as an alternative input method and the direct interaction with the screen as its primary function.

Question 7. What is microphone?
Answer: A microphone is an input device designed to convert sound, specifically voice, into electrical signals that a computer can understand and process. It allows users to feed audio inputs into the system. For example, it's used for recording speech or for online calls.
In simple words: A microphone is a device that takes your voice and turns it into sound signals a computer can use.

🎯 Exam Tip: Define a microphone as an input device for sound, specifically voice, that translates audio into a format usable by a computer.

Question 8. Write the names of output devices generally used.
Answer: Common output devices include:
Monitor
Printer
Speaker
These devices allow the computer to display or present information to the user in various forms. For instance, a monitor shows visuals, a printer produces hard copies, and speakers give audio.
In simple words: Monitor, printer, and speaker are some common output devices that show or play information from the computer.

🎯 Exam Tip: List the most common output devices (monitor, printer, speaker) as they are the primary means of user interaction.

Question 9. How many types of monitors are there?
Answer: There are mainly three types of monitors:
1. CRT monitor
2. LCD monitor
3. LED monitor
These types vary in their display technology, leading to differences in size, power consumption, and image quality. LED monitors are the most modern of these.
In simple words: There are three main kinds of monitors: CRT (older, bulky), LCD (thinner, lighter), and LED (most common now, energy efficient).

🎯 Exam Tip: When asked for types, simply listing them is sufficient, but briefly knowing the evolution (CRT -> LCD -> LED) shows deeper understanding.

Question 10. How is speed of lesser printer measured?
Answer: The speed of a laser printer is typically measured in PPM (Pages Per Minute) or sometimes CPM (Characters Per Minute). This indicates how many pages or characters the printer can produce within one minute. DPI (dots per inch) measures the print *resolution* or quality, not speed. A higher PPM means the printer can print faster.
In simple words: Laser printer speed is measured by how many pages it can print in one minute (PPM).

🎯 Exam Tip: Remember that PPM (Pages Per Minute) is the standard unit for printer speed. DPI (Dots Per Inch) is for print quality or resolution.

Question 1. What is CPU? How many parts of CPU are there?
Answer: The CPU, or Central Processing Unit, is like the "brain" of a computer. It is the most important part because it stores data, performs all types of calculations, and manages all the operations of the computer. The CPU has three main parts:
1. **Memory:** This part stores different kinds of data and instructions that the computer needs.
2. **A.L.U (Arithmetic and Logical unit):** This unit is responsible for all mathematical calculations (like addition and subtraction) and logical comparisons.
3. **Control unit:** This part oversees and directs all the operations and processes happening within the computer.
In simple words: The CPU is the computer's brain that stores, calculates, and controls everything. It has three parts: Memory, ALU (for math and logic), and the Control Unit (for managing tasks).

🎯 Exam Tip: When defining CPU, use "brain of the computer" as an analogy. Clearly list its three main parts and give a brief function for each to score full marks.

Question 2. Write the functions of different parts of Central Processing Unit.
Answer: The Central Processing Unit (CPU) has several parts, each with a specific function:
1. **Memory:** This component of the computer is where various types of data and instructions are stored temporarily or permanently. It holds information ready for the CPU to use.
2. **A.L.U (Arithmetic and Logical unit):** The primary function of the ALU is to perform both logical and comparative calculations. This includes arithmetic operations like addition, subtraction, multiplication, and division, as well as logic operations like checking conditions.
3. **Control unit:** The control unit manages and coordinates all the processes and operations that occur within the computer system. It directs the flow of data and instructions between the other parts of the computer.
In simple words: The CPU's Memory holds data, the ALU does all the math and logical thinking, and the Control Unit boss tells all parts what to do.

🎯 Exam Tip: For each part of the CPU, explain its function using action verbs: "Memory stores," "ALU performs calculations," and "Control Unit controls."

Question 3. What is OCR (Optical character recognition)?
Answer: OCR, which stands for Optical Character Recognition, is a technology used for very fast reading of printed, typed, or handwritten letters. It can read approximately 300 pages per hour using an optical or LASER scanner. This technique is most commonly used in places where a large number of bills or documents need to be processed quickly. It converts images of text into machine-readable text.
In simple words: OCR is a technology that reads text from pictures or paper quickly, turning it into digital text a computer can understand. It's used a lot for reading bills.

🎯 Exam Tip: When defining OCR, remember to state its full form and explain that it converts *images of text* into *editable text*, mentioning its speed and common applications like bill processing.

Question 4. What is OMR?
Answer: OMR, or Optical Mark Recognition, is a device used to detect the presence or absence of a pen or pencil mark on a piece of paper. It works by shining a light on the marked paper and then checking the reflected light pattern. This technology is specifically designed to read marks in designated boxes on printed cards or forms. OMR is an extremely important device for quickly checking large numbers of answer sheets in exams. This saves a lot of time compared to manual checking.
In simple words: OMR is a device that checks for marks made by pen or pencil on paper, like on exam answer sheets, by shining light and seeing how it reflects.

🎯 Exam Tip: Explain OMR's function as mark detection (not character recognition). Highlight its use in checking multiple-choice exam answer sheets or survey forms efficiently.

Question 6. What is a microphone or a web camera?
Answer:
**Microphones:** A microphone is an input device used to feed voice and other sounds as input into a computer system. It converts audio waves into electrical signals.
**Web Camera:** A web camera, or webcam, is an input device that captures video and still images. It allows a user to see and converse with another person over the internet, regardless of their location, displaying the activity on the computer screen. Webcams are essential for video calls and online meetings.
In simple words: A microphone lets you put your voice into the computer. A webcam lets you see and talk to people far away by showing their video on your screen.

🎯 Exam Tip: Treat each device separately in your explanation. For a microphone, focus on sound input; for a webcam, focus on video input and visual communication.

Question 7. What is a monitor? How many types of monitors are there?
Answer: A monitor, also known as a Visual Display Unit (V.D.U.), is the main output device of a computer. It displays visual information, such as text and graphics, generated by the computer. There are mainly three types of monitors:
1. CRT monitor
2. LCD monitor
3. LED monitor
These types represent the evolution of display technology, offering different levels of image quality, energy efficiency, and physical design.
In simple words: A monitor is the main screen that shows you what the computer is doing. There are three types: CRT (old, bulky), LCD (flat), and LED (latest, energy-saving).

🎯 Exam Tip: Define a monitor as the primary visual output device. When listing types, remember the historical progression and current common display technologies.

Question 8. LED monitors are most commonly used now a days, Why?
Answer: LED monitors are the most commonly used monitors today because of their excellent picture quality and low electrical consumption. They produce bright, clear images with good contrast. Additionally, they use Light Emitting Diodes (LEDs) for backlighting, which makes them very energy-efficient compared to older technologies. This combination of quality and efficiency makes them a preferred choice.
In simple words: LED monitors are popular because they show clear pictures and use very little electricity.

🎯 Exam Tip: When explaining why LED monitors are popular, focus on the two key advantages: good quality (clear picture) and energy efficiency (low power consumption).

Long Answer Type Questions:

Question 1. What is a mouse? What is its function?
Answer: A mouse is one of the most widely used input devices for a computer. Traditionally, it had a ball underneath that, when moved on a surface, would move the cursor (a small arrow) on the computer screen. Once the cursor reaches the desired position, clicking the mouse button helps to select instructions or objects that need to be processed. Today, optical mice, which do not have a ball and use a light sensor instead, are more commonly used. They make navigating and interacting with computer programs much easier.
In simple words: A mouse is a device that helps you point and click things on the computer screen. Moving it makes an arrow move, and clicking selects what you want to do.

🎯 Exam Tip: Define a mouse as an input device. Explain its function in terms of cursor movement and clicking for selection. Mentioning the transition from ball-mouse to optical mouse shows a good understanding of technology evolution.

Question 3. What is a printer? Explain any two commonly used printers.
Answer: A printer is an output device that produces a "hard copy" of digital information onto paper. This means it takes what is on the computer screen and puts it into a physical, printed form. The commonly used types of printers include:
(a) **Laser Printer:** Laser printers are known for their high-quality printing. They print very quickly, and the speed of printing is often measured in DPI (dots per inch), which also indicates the resolution. They are ideal for sharp text and graphics.
(b) **Ink Jet Printers:** Inkjet printers create images by spraying tiny drops of liquid ink onto paper. However, the print quality of an inkjet printer is generally lower compared to a laser printer. Its printing speed is also typically slower than that of a laser printer.
In simple words: A printer makes a paper copy of what's on the computer. Laser printers print fast and with high quality. Inkjet printers spray ink to print, but they are usually slower and have a bit less quality.

🎯 Exam Tip: Define a printer as an output device making hard copies. When explaining types, compare them based on key aspects like quality, speed, and printing mechanism (laser vs. ink spray).