Worksheet Answers

1. Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation. Through the course of using the Internet and your computer, you may have come in to contact with computer viruses. A computer virus might corrupt or delete data on your computer, use your email program to spread itself to other computers, or even erase everything on your hard disk.

2. Data can be lost if:

• It will be corrupted by computer viruses.
• Computer will be hacked by unauthorized users and data will be deleted or altered.

3. To protect data you can:

• Add backup files on storage units such as disks or hard drives.
• Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it.
• You should send or store data only on wireless networks that use encryption because hackers don't need physical access to the network or its devices; anyone with a wireless-enabled portable computer and a high gain antenna can capture data and/or get into the network and access data stored there if the wireless access point isn't configured securely.

4. 3 features I've used in MS Excel:

• Excel spreadsheets help us make sense of large amounts of data. To make it easier to find what you need, you can reorder the data or pick out just the data you need, based on parameters you set within Excel. You could sort on first name (alphabetically), second name (alphabetically) or by the numbers (numerically).
• You can type the calculation you want to perform directly into the cell or the formula bar and when you press Enter the answer will show in the cell.
• Recommended pivot table. PivotTables summarize large amounts of Excel data from a database that is formatted where the first row contains headings and the other rows contain categories or values. The way the data is summarized is flexible but usually the Pivot Table will contain values summed over some or all of the categories.

5. 4 functions I've used in MS Excel:

• Sum function. Adding values in cells using formula. Example: =SUM(A3+A4)
• Average function. Finding average of selected cells with numbers.
• Max function. Finding biggest value from selected values.
• Min function. Finding smallest value from selected values.

6. 3 features I've used in MS Word:

• Grammar checking feature. Checks of correct spelling of words.
• Copy and Paste feature. Allows users to copy information from different sources and copy it to Word document.
• Insert chart. Allows users to insert different charts like Excel chart, bar chart, pie chart, etc.

7. Sensors used in weather forecasting:

• Digital temperature sensing. It's simply a digital thermometer.
• Digital rainfall monitoring.
• Ultrasonic anemometers. Measuring wind on surface.
• Ceilometers. Determine the height of the cloud base.

8.  Animation is where a series of still images are linked together as part of a timed sequence. This makes the image appear to move.

8 bits = 1 byte, a combination of 1's and 0's
1024 Bytes = 1 KB
1024 Kilobytes = 1 MB
1024 Megabytes = 1 GB

Three main tasks performed by a computer is input, processing and output.
The spreadsheets that you have created at school are stored on the hard disc drive in the computer.
The shortcut for copy is Ctrl+C and the shortcut for paste is Ctrl+V.
The shortcut to cut some text is Ctrl+X.
The shortcut to undo some changes is Ctrl+Z. The shortcut to print your document is Ctrl+P.
NIC stands for Network Interface Cards. To connect to a network, a computer uses a network interface card. NIC controls the wired and wireless connections of a computer to exchange information with other computers and the Internet.
URL means Uniform Resource Locator. It is the address of a web page. Each page has its own unique web address (URL). This is how your computer locates the web page that you are trying to find.
RAM stands for random access memory. It's a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.

Input devices:
Keyboard, mouse, scanner, digital camera, joystick.

Output devices:
Printer, projector, speaker, earphones.

Storage devices:
USB, CD, DVD, hard disk, magnetic tape.

References:

1. Microsoft. (2016). What is a computer virus?. Available: https://www.microsoft.com/en-us/security/pc-security/virus-whatis.aspx. Last accessed 21th Mar 2016.
2. Rhys, T. (2016). ways that data can be lost and how to prevent it..Available: http://www.slideshare.net/wolfblood11/research-the-ways-that-data-can-be-lost. Last accessed 21th Mar 2016.
3. Shinder, B. (2006). 10 things you can do to protect your data.Available: http://www.techrepublic.com/article/10-things-you-can-do-to-protect-your-data/. Last accessed 21th Mar 2016.
4. Kuriacou, C. (2014). 5 Features of Microsoft Excel you Should be Using. Available: http://learn.filtered.com/blog/5-features-of-microsoft-excel-you-should-be-using. Last accessed 21th Mar 2016.