11th Computer Science, Chapter - 1, Topic No. 3 - Computer Hardware (Q/A)

11th Class (HSSC-I) Computer SLO Based Key Point Notes

(National Book Foundation - As Federal Textbook Board, Islamabad 

Based on National Curriculum Pakistan 2024 and Onward prescribed by Federal Board of Intermediate and Secondary Education, Islamabad, and All Pakistan Boards) 

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Unit 1: Overview of Computer System

Topic No. 1.3: Computer Hardware:

Q1. What is Computer Hardware? 

Ans: 

Computer Hardware:

Physical components that can be seen and touched. It Included input devices, output devices, memory, processing, storage, etc.

Q2. What are input devices? give some examples.

Ans: 

input devices

Input devices provide data and instructions to the computer. It accepts data in human-readable form and converts it into machine-readable form.

Examples: keyboard, mouse, microphone, etc.

Q3. What is keyboard? Name the major divisions of keys on the keyboard.

Ans: The keyboard is the primary input device of the computer which is used to enter the text data. It has normally 104-108 keys which have four divisions:
1. Function Keys 

2. Alphanumeric Keys
3. Editing and Cursor Movement keys 

4. Numeric Keypad

Q4. What are the functions of the keyboard?

Ans: 

Keyboard:

• It is used to input data in the form of text.
  
• A keyboard has keys or buttons on it.
  
• It converts keys pressed to electric signals in digital form.
  
• It has alphabet keys, numeric keys, function keys, and special keys.
• Pointing Input Devices.
• Used to control the movement of the cursor on the screen.

Q5. What are pointing Devices?

Ans: Pointing devices are input devices that are used to point and select on-screen options of GUI. These allow free and fast movement of the pointer on the screen. Pointing devices include a Mouse and trackball. Touchpad etc.

Q6. What are the functions of the mouse? Write its types.

Ans: 

Mouse:

• It is the most common pointing device.
• It detects motion on a surface and translates it into the motion of the pointer on the screen.

Mouse Types:.

Mechanical mouse (having a ball rolling ), optical mouse (having optical sensors), wireless mouse, etc. It can perform an operation such as selection, moving objects, opening files, etc. by clicking, dragging, etc.

Q7. What are the functions of the trackball?

Ans: 

Trackball:

• It has a ball on top that is rolled with fingers.
• It is stationary on the surface.
• Also has buttons like a mouse performing similar operations.

Q8. What are the functions of the Joystick?

Ans: 

Joystick:

• It is used for playing games.
• It has a stick and buttons on it.
• The movement of objects on the screen is controlled by tilting the stick.

Q9. What are the functions of the Touch Screen?

Ans: 

Touch Screen:

• It can be used both as an Input and output device.
  
• Pressure-sensitive screen.
  
• A user interacts with the computer by touching the icons or text on the screen using fingers or a stylus.
• Mostly popular in smartphones, PDAs, navigators, tablet PCs, etc.

Q10. What are the functions of the Light Pen?

Ans: 

Light Pen:

• Similar to a pen having a photo sensor at its tip.
  
• It is used for pointing and drawing on the screen.
• Provides better control and accuracy than a mouse and touch screen.
  
• Used for designing and engineering purposes.

Q11. What are the functions of the TouchPad?

Ans: 

Touch Pad:

• It is a touch-sensitive surface.
  
• Sense the movement of fingers and control the pointer movement on the screen Accordingly.
  
• Used in laptop computers as an alternative to mouse.
  
• Also has two buttons like a mouse below it.

Q12. What are the functions of the Microphone?

Ans: 

Microphone:

• It is used for voice input.
  
• It converts audio signals into electrical signals.
  
• A sound card then converts electric signals into digital form.

Q13. What are the functions of the Digital Camera?

Ans: 

Digital Camera:

• It captures
•  pictures and stores them in digital form.
  
• It has a memory card for storage.
  
• The images captured can be downloaded to the computer.
  
• Some digital cameras have LCDs to view images and edit or delete them.

Q14. What are the functions of the Scanners? Write its types.

Ans: 

Scanners:

Scanners are optical input devices that convert hardcopy into softcopy. Scanners work on the phenomenon of reflection of light. It reads text or images from paper and stores them in a computer in digital form.

Types of scanners:

• Handheld scanner
  
• Flatbed scanner
  
• Barcode reader

Q15. What are the functions of the Handheld scanner?

Ans:

Handheld scanner:

• It is a handheld device that is moved over the image to be scanned.
  
• It must be moved with uniform speed to provide an image without distortion.
  
• They are slower than flatbed scanners.
  

Q16. What are the functions of the Flatbed scanner?

Ans:

Flatbed scanner:

• It can scan entire images at a time.
  
• The image is placed face down on the glass and covered with a lid.

Q17. What are the functions of the Barcode reader?

Ans:

Barcode reader:

• It scans bar code or UPC (Universal Product Code) on products.
  
• The barcode has information about the product like expiry date, price, etc.
  
• This information is given to computers for generating bills which makes faster checkouts.
  

Q18. How are Barcode readers used in shopping malls?

Ans: 

Bar code readers are used for billing at checkouts in shopping malls. These are used to read Bar Codes on products (also known as Universal Product Code or UPC). These help in quick and error-free billing.

Q19. Briefly describe the magnetic strip cards.

Ans: Magnetically encoded data on the back side of the card is known as a magnetic strip card. It can be used to retrieve the personal information of the cardholder securely. It is used as a Personal Identity Card, Debit card, Credit Card, etc.

Q20. What are the functions of the Magnetic Strip Card Reader?

Ans:

Magnetic Strip Card Reader:

• It reads information on a magnetic strip located on a plastic card.
  
• Information is stored in the form of magnetized spots.
  
• Information can be read by swiping the cards on the reader.
  

Examples: ATM cards, credit cards, driving licenses, etc.

Q21. What are Output Devices and write their types? 

Ans:

Output devices display useful information.

Types of Output Devices:

Softcopy output: It is displayed on a screen in the form of text, images, video, etc.

Hardcopy output: It is in printed form on paper by a printer or plotter.

Sound output: sound output generated through speakers in the form of sound.

Q22. What are Monitors? write some features of monitors.

Ans:

• Also called VDU( Video Display Unit)
• It produces soft copy output. (text, graphics, video, animations, etc.)

Features:

1. Size: The monitor varies in size from 15 to 21 inches.
2. Colour: monitor can be black and white or RGB (colored).
3. Pixel: stands for picture element. It is a small dot on the monitor forming an image.
4. Resolution: numbers of pixels per square inch. The higher the resolution better the image quality.
5. Dot pitch. Distance between two pixels on the screen. A smaller dot pitch means higher resolution.

Q23. Write some types of Monitors.

Ans:

Types of monitor:
CRT, LCD, LED, etc.

Q24. What are CRT (Cathode Ray Tube) Monitors.? Briefly explain.

Ans:

• Similar to standard television sets.
  
• Heavier and consumes more power.
  
• It is a vacuum tube having an electron gun and a phosphor-coated screen.
  
• An electron gun sprays a beam of electrons which glows the phosphor-coated screen when striking it.
• Colored monitors have three electron guns and phosphor atoms (Red, Green, and Blue) RGB.
• The remaining colors are produced by the combination of Red, green, and blue.

Q25. What is LCD (Liquid Crystal Display)? Briefly explain.

Ans:

• It is thin and lightweight.
  
• They have better resolution and emit less radiation than CRT.
  
• They are portable, less expensive, reliable, and less harmful to the eyes than CRT.
  
• It has a fluid-like substance called liquid crystal between two sheets.
  
• These molecules are lined up on the screen and have two states.
  
• either they allow or block the light to produce images on the screen.
  
• They are used in, laptops, monitors, phones, clocks, etc.

Q26. What is LED (Light Emitting Diode)? Briefly explain.

Ans:

• It uses LED (Light Emitting Diode) as pixels.
  
• Lighter in weight and consumes less power than LCD.
  
• Better resolution and emit less radiation.
  
• Long-lasting and reliable.
  
• Expensive than other monitors

Q27. What is a Printer? Write its types.

• Produce hardcopy output.
  
• Connected to computers through parallel or USB ports.
• Print quality, print speed, printing graphics.
  

Types of Printers:

• Impact printers
  
• Non-impact printers
  

Q28. What are Impact printers?

Ans:

• Work like a typewriter.
  
• Image is produced when the print head strikes against the paper.
  
• Impact printers have low print quality
  
• they produce a lot of noise.
  
• They are slow and poor ability to print graphics.

Example: Dot matrix and chain printers

Q29. What are Dot matrix Printers?

Ans:

• The dot matrix has 9 to 24 pins on its print head.
  
• Its print quality depends upon the number of pins.
  
• Not very popular nowadays.
  

Q30. What are Chain printers?

• They are line printers. (can print one line at a time).
  
• It contains a character on a chain that moves very fast.
  
• The image is produced when a set of hammers strike against an ink ribbon on paper.

Q31. What are Non-impact printers?

Ans:

• They produce images without striking the paper.
• They are fast (print an entire page at a time).
• Better print quality than impact
• Produce very little noise while printing.
• Expensive than impact printers.
• Better ability to print graphics.

Examples: laser printers and inkjet printers.

Q32. What are Laser printers?

Ans:

• Print technology is similar to photocopiers.
  
• They are very fast and silent.
  
• Print an entire page at a time.
  
• Print quality is very high.
  
• Also, print colored graphics.

Q33. What are Inkjet printers?

Ans:

• They produce images by spraying tiny drops of ink on paper.
  
• Less expensive and slower than laser printers.
  
• Print quality is also less than laser printers.
  
• Can produce colored prints cheaper than laser printers.
  

Q34. What are Plotters?

Ans:

• Produce large-scale hardcopy output.
  
• Used in architectural drawings, maps, graphs, civil engineering drawings, and panaflexes.

Examples: flatbed plotters and drum plotters.

Q35. What are Flatbed plotters?

Ans:

• Paper is spread and fixed on a rectangular flat surface.
• It has a mechanical arm holding different colored pens.
• Which is moved on the surface to draw the image.

Q36. What is a Drum Plotter?

Ans:

• It has a rotating drum.
  
• The sheet is fed from one side of the drum.
  
• The drum rotates to move the paper.
  
• It produces large-size panaflexes.

Q37. What are Speakers?

Ans:

• Produce audio output.
  
• Attached to the sound card on the motherboard.
  
• Convers electric signals in sound form.

Miscellaneous Question:

Q38. Differentiate between CRT and LCD?

Ans:

CRT	LCD
Cathode Ray Tubes use electron beams to produce output	Liquid Crystal Displays use a special type of liquid to display the output
These are bulky in size	These are compact in size
CRTs are heavier in weight	LCDs are lighter in weight
CRTs are not portable	LCDs are portable
CRTs have high power consumption	LCDs have low power consumption
CRTs emit harmful radiation	LCDs do not emit harmful radiation
CRTs are less expensive than LCD	LCDs are expensive
CRTs have larger view angle	LCD has a smaller view angle

Q39. Why LEDs are a better choice over CRT and LCD? Give any Three Reasons.

Ans:

1. LEDS produce a very bright image
2. LEDs can be operated on low power
3. LEDs run at a lower temperature
4. LEDs emit less radiation
5. LEDs have a longer lifespan

Q40. Why Dot-matrix printers are becoming obsolete?

Ans:

Dot-matrix printers are impact printers and are noisy, slow speed low-quality printers. The main reason these are becoming obsolete is their noise and low quality.

Q41. Differentiate between Impact and Non-impact Printers.

Ans:

Impact Printers	Non-impact Printers
Impact Printers are slow in speed	Non- Impact Printers are faster in speed
Impact Printers are noisy	Non- Impact Printers are not noisy
Impact Printers can produce only text	Non-impact printers can produce text as well as graphics
Impact Printers are less expensive	Impact Printers are expensive
Impact Printers produce low-quality output	Non- Impact Printers produce high quality output
Print head physically strikes the paper for printing	The print head physically does not strike the paper for printing
Examples are Dot-Matrix, Daisy wheel, Drum and Chain Printers	Examples are Ink-jet, Laser, and Thermal Printers

Q42. Give any three advantages of Laser Printers over Dot-Matrix Printers.

Ans: 

1. The Laser Printer is not as noisy as the Dot-Matrix Printer
2. Laser Printers can produce text as well as graphics while Dot-Matrix can print only text.
3. Laser Printers produce high quality while Dot-matrix produces low quality 

Q43. Give any three uses of plotters.

Ans: 

1. Plotters are used to print larger drawings.
2. Plotters are used to print maps and architectures.
3. Plotters are used to print blueprints of internal structures of heavy machinery and aircraft.

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