Informatics Practices (065) Term – II 2022 Answer Key
[By Anjeev Singh| Date: 13-06-2022]
(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.
Answer: 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 whereas internet is a collection of various devices.
What are Cookies? How can we disable Cookies?
Answer: A cookie is a text file, containing a string of information, which is transferred by the website to the browser when we browse it.
This string of information gets stored in the form of a text file in the browser. The information stored is retransmitted to the server to recognise the user, by identifying pages that were visited,
Cookies can be disabled by changing the Privacy and Security settings of our browser.
(i) What is the function of a Gateway?
Answer: Gateway serves as the entry and exit point of a network, as all data coming in or going out of a network must first pass through the gateway in order to use routingpaths. Gateway is used to connect two dissimilar network.
(ii) Give examples of any two plug-ins.
Answer: Flash and Java
Find the output of the following SQL Queries:
i) SELECT ROUND (7658.345,2);
ii) SELECT MOD(ROUND (13.9,0),3);
Give any two differences between the POWER() and SUM() SQL functions.
|1. The POWER () function returns the value of a number raised to the power of another number. 2 It accepts two parameters: a number (base) and an exponent (power)||1. The SUM () function calculates the sum of a set of values|
2. It accepts the range of numbers or bunch of values
Give one advantage and disadvantage to each of Bus and Star topology.
|STAR TOPOLOGY||BUS 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);
Answer: INDIA MOVEMENT
(ii) SELECT INSTR(“ARTIFICIAL INTELLIGENCE”, “IA”);
Srikanth created the following table STUDENT in his database.
Table : STUDENT
He now wants to count the 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.
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.
Answer : SELECT LTRIM(NAME) FROM SCHOOLDATA;
(ii) Display the names of students who were born on Sunday.
Answer: 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;
LEFT(Gender,1) | Name
F | Swpanil Pant
M | Rahil Arora
SECTION – B
(Each question carries 3 marks)
Predict the output of the following SQL queries
(i) SELECT TRIM(” ALL THE BEST “);
TRIM( “ALL THE BEST”)
ALL THE BEST
(ii) SELECT POWER(5,2);
(iii) SELECT UPPER (MID(“start up india”,10);
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.
SELECT UPPER(BREED) FROM MYPET;
SELECT UCASE(BREED) FROM MYPET;
(ii) Display the total price of all the pets.
Answer: SELECT SUM(PRICE) FROM MYPET;
(iii) Display the average life span of all the pets.
Answer: 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.
Answer: LOWER() / LCASE()
(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”;
10 + MOD(QUANTITY,3)
(ii) SELECT ROUND(PRICE, 2)*QUANTITY FROM PRODUCT WHERE QUANTITY > 2;
(iii) SELECT UCASE (RIGHT(PNAME,2)) FROM PRODUCT;
SECTION – C
(Each question carries 4 marks)
Consider the table: ITEM
Write SQL queries for the following:
(i) Display all the records in descending order of Stockdate.
(ii) Display the Type and total number of items of each Type.
(iii) Display the least Price.
(iv) Display the Itemname with their price rounded to 1 decimal place.
(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
Predict the output for the following SQL queries:
(i) SELECT MAX(Qtysold), MIN(Qtysold) FROM SALESMAN;
MAX(Qtysold) | MIN(Qtysold)
280 | 68
(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) Count the total number of salesman.
Answer : SEELCT AREA,MAX(QTYSOLD) FROM SALESMAN GROUP BY AREA;
(ii) Display the maximum qtysold from each area.
Answer : SELECT COUNT(*) FROM SALESMAN;
(iii) Display the average qtysold from each area where number of salesman is more than 1.
FROM SALESMAN GROUP BY AREA
HAVING COUNT(*) > 1;
(iv) Display all the records in ascending order of area.
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:
The school also has a branch in Mumbai. The school management wants to connect all the wings as well as all the computers of each wing (W1, W2, W3, W4).
Distances 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.
Cable Layout-1: Tree Topology (Features: high speed, W4 connected to the server via w2, dependency is there)
(Required Cable length: 150m)
Cable Layout 2: Star Topology (Features: high speed, directly connected with server, No dependency)
(Required Cable length: 295 m)
(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.
Answer: (a) LAN (b) WAN
(iii) Suggest the placement of the following devices with justification:
Answer: As per cable layout-1 No repeater is required . As per cable layout-2 Repeater is required between w1 and w4
Answer: Switch or Hub can be placed in each wing.
(iv) 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.
Answer: Protocol for sending the voice signals over the internet: VoIP
To send messages instantly: Use any chat or IM Software like WhatsApp, Slack, Skype, Yahoo Messenger, Google Talk, Facebook Messenger, Google Hangout