In this article, I am going to discuss Answer Key Informatics Practices Class 12. This is not a final marking scheme but it is prepared by us according to our knowledge and experience. All answers are relevant answers according to the questions and best of my knowledge of Answer Key Informatics Practices Class 12.
Answer Key Informatics Practices Class 12
The questions paper of CBSE board is based on Term 2 CBSE Sample Paper 2022.
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Let us start the article Answer Key Informatics Practices Class 12 section A which contains each question of 2 marks.
(Each question carries 2 marks)
 Rushil thought “WWW and “Internet” are synonyms i.e., they meant same and can be used interchangeably. But the teacher said that they are not same. Help him to understand the meaning of both the terms with the help of a suitable example of each.
WWW stands for Word Wide Web. It is an ocean of informtion stored in the form of trillions of interlinked web pages and web resources. These resources can be accessed via internet.
The internet is network of networks. It is global network of various computing devices.
So WWW is collection of web documents where as internet is a collection of various devices.
What are Cookies? How can we disable Cookies?
A cookie generally contains 2 bits of data: ID for every user, and a website name.
Cookies alter websites to retrieve this information after you return them, in order that they’ll keep in mind you and your preferences and tailor page content for you supported this information.
On your computer, open Chrome.
At the top right, click More Moreand then Settings.
Under “Privacy and security,” click Site settings.
From here, you can:
Turn on cookies: Next to “Blocked,” turn on the switch.
Turn off cookies: Turn off Allow sites to save and read cookie data.
 i) What is the function of a Gateway?
Ii) Give examples of any two plug-ins.
i) Gateway is used to connect two dissimilar network.
ii) Java, Adobe Flash Player, Shockwave, Silverlight
 Find the output of the following SQL Queries:
i) SELECT ROUND (7658.345,2);
ii) SELECT MOD(ROUND (13.9,0),3);
i) round (7658.345,2)
Give any two differences between the POWER() and SUM() SQL functions.
1. It is used to compute power of given number by specified digit.
2. It accepts two parameters: a number and a power
1. It is used to do sum of specified numbers or range of numbers
2. It accepts the range of numbers or bunch of values
 Give one advantage and disadvantage to each of Bus and Star topology.
Advantage: Easy to install
Disadvantage: More cables required
Advantage: Short Cable length
Disadvantage: Difficult to detect a fault
 Find the output of the following SQL. queries
(i) SELECT SUBSTR(“FIT INDIA MOVEMENT”,5);
(i) SELECT INSTR(“ARTIFICIAL INTELLIGENCE”, “IA”);
i) SUBSTR(“FIT INDIA MOVEMENT”,5)
ii) INSTR(“ARTIFICIAL INTELLIGENCE”, “IA”)
 Srikanth created the following table STUDENT in his database.
Table : Student
He now wants to count number of students in each class where the number of students is more than 3. He has executed the following query:
SELECT MAX (Marks) FROM STUDENT WHERE COUNT (*) >3 GROUP BY Class
But, he got an error. Identify the error(s) and rewrite the query. Also underline the correction(s) done.
select count(*) from student group by class having count(*)>3;
 Ms. Mohini is working in a school and stores the details of all students in a table SCHOOLDATA.
Write SQL statements from the above-given table to:
(i) To remove leading spaces from the column Name.
(ii) Display the names of students who were born on Sunday.
(i) select ltrim(name) from schooldata;
(ii) select name from schooldata where dayname(dob)=’Sunday’
Predict the output of the following SQL queries from the given table SCHOOLDATA
(i)SELECT MAX(Percent) FROM SCHOOLDATA;
(ii) SELECT LEFT(Gender,1), Name FROM SCHOOLDATA WHERE YEAR (Dob)=2005;
(ii) left(Gender,1) Name
F Swpanil Pant
M Rahil Arora
In the next section of Answer Key Informatics Practices Class 12 we discuss Section B 3 marks questions. Let us begin!
SECTION – B
(Each question carries 3 marks)
 Predict the output of the following SQL queries
(i) SELECT TRIM(” ALL THE BEST “);
(ii) SELECT POWER(5,2);
(iiI) SELECT UPPER (MID(“start up india”,10);
(i) trim(” ALL THE BEST “)
ALL THE BEST
(iii)UPPER( MID(“start up india”,10))
Consider a table “MYPET” with the following data:
Write SQL queries for the following:
(i) Display the Breed of all the pets in uppercase.
(ii) Display the total price of all the pets.
(iii) Display the average life span of all the pets.
(i) select upper(breed) from mypet;
select ucase(breed) from mypet;
(ii) selct sum(price) from mypet;
(iii) select avg(lifespan) from mypet;
 Write the names of SQL functions to perform the following operations:
(i) Display name of the Month from your date of birth.
(ii) Convert email-id to lowercase.
(iii) Count the number of characters in your name.
 Consider the following table PRODUCT:
Find the output of the following SQL queries
(i) SELECT 10+MOD(QUANTITY,3) FROM PRODUCT WHERE PNAME = “Eraser”;
(ii) SELECT ROUND(PRICE,2)*QUANTITY FROM PRODUCT WHERE QUANTITY > 2;
(iii) SELECT UCASE (RIGHT(PNAME,2)) FROM PRODUCT;
In the next section of Answer Key Informatics Practices Class 12 we discuss Section C.
SECTION – C
(Each question carries 4 marks)
 Consider the table: ITEM
(i) select * from item order by stockdate desc;
(ii) select type, count(*) from item group by type;
(iii) select min(price) from item
(iv) select itemname, round(price,1) from item;
 Consider the following table Table : SALESMAN
(ii) SELECT COUNT (Area) FROM SALESMAN;
(iii) SELECT LENGTH (Sname) FROM SALESMAN WHERE MONTH(Dateofjoin)=10
(iv) SELECT Sname FROM SALESMAN WHERE RIGHT(Scode, 1)=5;
Based on the given table SALESMAN write SQL queries to perform the following operations:
(i) Display the maximum qtysold from each area.
(ii) Count the total number of salesman.
(iii) Display the average qtysold from each area where number of salesman is more than 1.
(iv) Display all the records in ascending order of area.
(i) seelct area,max(Qtysold) from salesman group by area;
(ii) select count(*) from salesman;
(iii) select avg(qtysold) from salesman group by area having count(*)>1;
(iv) select * from salesman order by area;
 ABC International School, Delhi has different wings Administrative Wing (W1), Primary Wing (W2), Middle Wing(W3) and Secondary Wing(W4) as shown in the diagram:
Distance between the wings are as follows:
|W3 to W1||85 m|
|W1 to W2||40 m|
|W2 to W4||25 m|
|W4 to W3||120 m|
|W3 to W2||150 m|
|W1 to W4||170 m|
Number of computers in each of the wing:
Based on the above specifications, answer the following questions:
(i) Suggest the topology and draw the most suitable cable layout for connecting the Delhi branch’s wings. (ii) Suggest the kind of network required (out of LAN, MAN, WAN) for connecting
(a) Administrative Wing (W1) with Middle Wing (W3)
(b) Administrative Wing (W1) with the Mumbai branch.
(iii) Suggest the placement of the following devices with justification:
(v) Due to pandemic school had to adopt Online classes. Suggest the protocol that is used for sending the voice signals over internet. Also, give an example of an application of WwW that helped the teachers
to send messages instantly to the students.
(i) Star topology
(iii) (a) As per cable layout given Repeater can be placed in between W3 and W4 wing.
(b) Hub or switch can be placed in each wing.
(iv) VoIP and Any chat or IM Software like whatsapp
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