Computer Studies :: Computer - Hardware and Software
Unit - 2 : External Hardware
EXERCISE
Objective
I. Choose the correct option:
1. Which of the following is called the physical part of a computer system?
a) Hardware. [✓]
b) Utility programs. [ ]
c) Application software. [ ]
d) System software. [ ]
2. What type of device is a computer mouse is?
a) Communication device. [ ]
b) Output device. [ ]
c) Pointing device. [✓]
d) System device. [ ]
3. Which of the following devices is used to track the movement of people for security purposes?
a) Digital camera. [ ]
b) Webcam. [ ]
c) CCTV camera. [✓]
d) Phone camera. [ ]
4. Which of the following is the most appropriate statement of dot matrix printer?
a) It is very costly. [ ]
b) Printing quality is very high. [ ]
c) It prints the characters or images by a striking mechanism. [✓]
d) It is a non-impact printer. [ ]
5. What another name is given to a pen drive?
a) Flash drive. [✓]
b) Small drive. [ ]
c) Hard drive. [ ]
d) Soft drive. [ ]
II. State whether the following statement are True/False:
1. Input devices are used to feed the data and instructions in the computer system. [T]
2. A mouse is known as a pointing device. [T]
3. You can not receive or send fax through an all-in-one printer. [F]
4. A cordless mouse or keyboard works within a short range of distance from your computer system. [T]
5. A scanner can be compared to a photocopy machine. [T]
6. A light pen is used in computer aided designing (CAD). [T]
7. A scanned image can not be sent to an email editor. [F]
8. Digital photographs have low resolutions as compared to other photographs. [F]
9. A touch screen is a menu driven input device. [T]
10. A liquid crystal display screen consumes less power and also radiates less heat. [T]
III. Write the full forms of the following:
1. LCD : Liquid Crystal Display.
2. SD CARD : Secure Digital Card.
3. CPS : Characters Per Second.
4. CAD : Computer Aided Design.
5. RPM : Revolution Per Minute.
6. CRT : Cathode Ray Tube.
IV. Name the following:
1. Four input devices.
a) Keyboard.
b) Mouse.
c) Light Pen.
d) Scanner.
2. Four output devices.
a) Visual Display Unit.
b) Printer.
c) LCD Projector.
d) Headphones.
3. Two types of impact printers.
a) Dot Matrix Printer.
b) Daisy Wheel Printer.
4. Two types of non-impact printers.
a) Inkjet Printer.
b) Laser Printer.
5. Two pointing devices.
a) Mouse.
b) Light Pen.
6. Two secondary storage devices.
a) Solid State Drive(SSD).
b) Compact Disc.
V. Case-Study based questions:
Unsolved
1. There are some devices in a computer system which are used to give out the result of data processing. A popular output device about which you would be well aware of resembles a TV screen. In case, the output is to be displayed on a big screen for showing it to numerous people, an LCD projector is used. Other than these devices, we can also use printers (impact and non-impact) to produce the output on paper.
Based on the above case, answer the following questions:
a) Which of the following devices resemble a TV screen?
i) Touch sensor. [ ]
ii) VDU. [✓]
iii) MCB. [ ]
iv) All of these. [ ]
b) Which device produces result on paper with hammering effect?
i) LCD projector. [ ]
ii) Laser printer. [ ]
iii) Dot Matrix Printer. [✓]
iv) Inkjet Printer. [ ]
c) Which of the following devices produce result without making any sound?
i) Impact printer. [ ]
ii) Character printer. [ ]
iii) Dot Matrix printer. [ ]
iv) Laser printer. [✓]
d) Which of the following devices is used to display presentation in a hall or a gallery?
i) Digital camera. [ ]
ii) Laptop screen. [ ]
iii) LCD projector. [✓]
iv) Seven segment display. [ ]
Subjective
I. Define the following terms:
1. SD card:
= The SD Card (Secure Digital Card) is an ultra-small flash memory/a non-volatile memory card designed to provide high-capacity memory.
2. Mouse:
= Mouse is a pointing device. We can move the pointer on the screen with the help of the mouse and by clicking provide input to the system.
3. Scanner:
= Scanner is an input device that scans documents, images, etc. from the source and converts it into digital data. The data can be saved on to the disks for further processing.
4. Visual Display Unit:
= A Visual Display Unit (VDU) is one of the most common output devices. A VDU is similar to a television screen having a cathode ray tube (CRT). A cathode ray tube consists of three main parts:
i) Electron Gun.
ii) Deflecting Plates.
iii) Fluorescent Screen.
5. LCD Projector:
= A liquid crystal display (LCD) projector is an output device used to magnify the presentations prepared on a computer. It accepts the data/information from the CPU.
6. Inkjet Printer:
= Inkjet printer is the most common non-impact printer. It works in a similar manner as a dot matrix printer. A very fine stream of ink is ejected through a fine nozzle.
7. Light Pen:
= Light Pen is a pointing device which has a pen-like structure. Inside the pen, there is a photo sensor which detects light. The pen is placed on the screen of the monitor that sends light signal.
II. Differentiate between the following:
1. Impact printers and Non-impact printers.
=
Impact Printer | Non-Impact Printer |
|---|---|
1. It forms characters by striking a print hammer against an inked ribbon. | 1. It forms characters without making direct contact with the paper. |
2. It uses either ribbon or carbon paper. | 2. It uses ink cartridges. |
3. It makes noise while printing. | 3. It prints smoothly on the paper. |
2. Input devices and Output devices.
=
Input Devices | Output Devices |
|---|---|
1. A computer uses the input devices to accept the data and instructions. | 2. A computer uses the output devices to give the results of any processed data. |
2. We can control the input devices. | 2. Output devices are controlled by the computer. |
3. Most necessary input devices are keyboard, mouse etc. | 3. Most necessary output devices are monitor, speaker, printer etc. |
3. Keyboard and Mouse.
=
Keyboard | Mouse |
|---|---|
1. Keyboard is a type writing device. | 1. Mouse is a pointing device. |
2. Keyboard has around 104 keys to input data. | 2. Mouse has two buttons and a wheel to point and scroll. |
3. We can do almost all the works of a mouse by a keyboard. | 3. It is difficult to do all the tasks of a keyboard by only using a mouse. |
III. Long Answer Question.
1. What is a printer? What are its types?
= Printers are the common output devices used to get the results on paper (hard copy). They provide information in a permanent and readable form. The data/information is transformation is transferred from the main memory of the computer to the printer and then printed on the paper.
Printers are of two types - Impact Printers and Non-Impact Printers.
Impact Printers are of three types - Dot Matrix Printers, Line Printers and Daisy Wheel Printers.
Non-Impact Printers are also of three types - Inkjet Printers, Laser Printers and Thermal Matrix Printers.
2. Explain the three functions of a scanner.
= The three functions of a scanner are -
1. Scan : To capture the document that can be saved as a digital file.
2. Copy/Print : To scan the document and send it to the printer to get a hard copy at the same time.
3. Share : To scan the document and share it with others.
3. How is a web camera useful to us?
= Webcams are the most common video capturing devices connected to computers or computer networks, often using a USB port.
A web camera can be used for video chatting over the internet. It allows real-time communication from anywhere in the world. Webcams are also used for security purposes and to reach millions of mainstream computer users worldwide.
4. Explain the working principle of a Laser printer.
= In a laser printer, a low-power laser beam is used to create an image of the page to be printed on the photo-conducting surface of a rotating drum. A special ink (toner) is used which is attracted to the laser-exposed surface of the drum. When the paper comes in contact with the drum, the image is fixed on to the paper.
5. What is meant by a flash drive? Why is it so popular?
= We have been using CD as a portable data storage device. In 1998, IBM came out with the latest portable data storage device known as thumb drive or a flash drive.
Unlike RAM, a thumb drive is re-writable and holds the data in memory without power supply. It fits into any USB (Universal Serial Bus) port of a computer. The drive is small, often of the size of a human thumb and is a very stable memory storage device. We can save text, music, documents and photos in this device. The storage capacity of a thumb drive is 256 GB or more. It is an ideal data storage device because at a low price it offers long-term storage.
6. What are the points to be considered while selecting a printer?
= The selection of a printer depends on the following features:
❐ Quality of printing : It means whether the impression of characters on paper is in the form of dots or latter quality.
❐ Speed of printing : It refers to the speed with which the printing of characters takes place on the paper. This specification is decided by CPS (Character Per Second) or RPM (Revolution Per Minute) marked on a printer.
❐ Type of printer : It means whether it is an impact printer or a non-impact printer.
❐ Cost of printer : Of course, the cost matters while selection a printer. But, we always look for the cheap and best quality to fulfil our requirements.