Std 7 - Chapter - 5 Computer Virus

Chapter - 5

Computer Virus

1.	What are the symptoms of a computer virus?
	Symptoms of a virus include computer lockups, screen distortions, data loss, and unusual messages and reduced computer performance.
2.	What is an antivirus program?
	Antivirus programs check the files on your computer for viruses and also remove the entire virus.
3.	What is the full form of VIRUS?
	Vital Information Resources Under Seize
4.	What is a computer virus?
	Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.
5.	Write the names of any three Antivirus software
	Norton Antivirus, Kaspersky, and McAfee
6.	What is a Boot sector virus?
	Boot sector viruses affect the boot sector area of a hard disk.
7.	Write short notes on: Worms, Trojans
	Worms: A worm is a malicious program that duplicates itself. They eventually fill up the disks space with copies of itself and thereby make a computer system to work very slowly. Trojans: These viruses at first appear to be friendly but are very malicious programs.  They steal information from the computer.
8.	Why it is necessary to scan an external device attached to your computer, before using it?  Describe the process of scanning it.
	Because external devices may contain viruses, that affects our computers. Step 1. Double Click the Kaspersky Anti-Virus. Step 2. Click Scan option Step 3: Click the Full Scan option to scan all the drives of your computer.
9.	What precautions should you take to protect your computer from a virus?
	·         Do not use a CD or pen drive received from another person unless you are certain that the disk does not contain a virus. ·         Do not download programs or other information from non-reputed sources on the Internet. ·         Restrict access to your system. ·         Install Antivirus programs on your computer.
10.	Why is it necessary to update your Anti-Virus software?
	New viruses appear often.  You must keep updating your antivirus software regularly to fight against these new viruses.
11.	What are ‘bombs’ in connection with virus?
	Bombs are viruses which activate themselves after a specific time period and cause damage to the computer system.
12.	What do you mean by a macro virus?
	Macro viruses are written in the scripting languages for Microsoft programs such as MS Word and MS Excel.  These viruses spread by Excel spreadsheets and other Microsoft Office documents.
13.	How do computer viruses attack our computers?
	·         Through an infected CD or Pen drives. ·         Through e-mail attachments. ·         Visiting malicious website and downloading infected files. ·         Starting an infected application as it infects other running applications.

Std 7 - Chapter - 4 Charts in MS Excel 2007

Chapter - 4

Charts in MS Excel 2007

1)	What happens to a chart when you change the data or text in a worksheet?
	Any changes in the worksheet will automatically update the chart.
2)	How do you change the chart type?
	a)      Double click the chart.  The Design tab opens b)      Click the Change Chart Type in the type group c)      Choose the new Chart Type and its Subtype
3)	Mention any three subtypes of Pie charts.
	Pie-in 2 D Pie-in 3 D Exploded Pie
4)	How do you resize a chart?
	To resize a chart proportionally, drag the corner handle on the chart diagonally.
5)	What is a chart?
	A picture showing numeric data is called a chart or graph. Charts are more attractive and appealing than simple representation of data.
6)	How do you delete data from a chart?
	By deleting the data from the related worksheet, we can delete the data from a chart too.
7)	How do you create a chart in Excel?
	a)      Select the cells within the table. b)      Click the Insert tab on the Ribbon. c)      Select the type of chart you want from the Charts group. d)      Select the chart subtype from the drop down list.
8)	Explain the following charts
	a)      Line Chart A Line chart shows trends in data at equal intervals.  It shows data in different styles of lines varying at equal intervals. b)      Pie Chart A pie chart shows one data series in the form of the comparative size of things that make up the data series to the sum of the items. c)      Column chart A column chart shows data changes over a period of time or illustrates comparisons among items.
9)	Name the different tabs that appear when charts get created.
	a)      Design Tab b)      Layout Tab c)      Format Tab
10)	Name the locations where charts can be created?
	Charts can be created on the current worksheet, as an object in separate sheet or in the current workbook.

Std 7 - Chapter - 3 - More on MS Excel 2007 - Formulae and Functions

Chapter - 3

More on MS Excel 2007 – Formulae and Functions

1.	What do you understand by the term Conditional Formatting?
	This feature allows us to format the data in the worksheet depending on if it satisfies a certain condition.
2.	What are functions?
	Functions are predefined commands that act on a cell or range of cells and perform some particular operation quickly.
3.	Define the term filtering?
	Filtering is a quick way to find a set of data in a range.
4.	What is cell referencing?
	Cell referencing means how a cell address behaves in the formulae when it is copied from one cell to the other.
5.	What do the following functions do? Explain with proper syntax and example of each.
	a)      SUM: It adds all the numbers in a given range of cells. Syntax: =SUM(range or numbers) Example: =SUM(A1:A5) b)     AVERAGE: It calculates the average of the numbers in a given range of cells Syntax: =AVERAGE(range or numbers) Example: =AVERAGE(A1:A5) c)      MIN: It returns the smallest value in a given range of cells. Syntax: =MIN(range or numbers) Example: =MIN(A1:A5) d)     MAX: It returns the largest value in a given range of cells. Syntax: =MAX(range or numbers) Example: =MAX(A1:A5)
6.	What is the use of IF function? Explain with an example.
	The IF function checks to see if a condition you specify is true, or false. The IF function returns the first value if the condition specified evaluates to TRUE and the second value if it evaluates to FALSE. Syntax: =IF(condition, value_if_True, value_if_False) Example 1: =IF(A1>50, 150,100) Example 2: =IF(A2=100, A2*10,”LOW”)
7.	What is Sorting? In how many ways you can sort your data?
	Sorting means to arrange data either in ascending or descending order. Excel allows you to sort by date, sort by text or numbers, sort by multiple columns, or by colour. And, if you like, you can even colour code your data.
8.	Define the following with an appropriate example of each.
	a)      Relative referencing: in this referencing both column part and row part are not fixed. E.g. if the formula in D4 is =B4*C4, when the formula is copied vertically notice that the cell address in the formula is automatically changed. (Pg. No 36) b)      Absolute referencing: in this referencing both column part and row part are fixed.  E.g. if the formula in D4 is =$B$4*2 and when it is copied to the lower rows, there is no change in the cell address. (Pg. No 37) c)      Mixed referencing: in this referencing either column part or row part is fixed.  E.g. $B4 is a mixed cell reference with absolute column and relative row and C$4 is a mixed cell reference with relative column and absolute row. (Pg. No 37)
9.	Write the steps to apply Custom Filter on a range of cells.
	Step 1: Click Data tab – filter Step 2: Click the arrow in the column heading. Step 3: Select Number Filters from the list. Step 4: Click Custom Filter, Custom AutoFilter dialog box appears. Step 5: Choose the option according to the condition you want. Step 6: Too add another criteria, click Add Step 7: Specify the second condition in the same way. Step 8: Click OK button to view the rows according to the specified conditions.