Solved Board Paper For CBSE Class 12 Informatics Practices

a) The output of the following code will be: [1,2,3,4]

b) Data pivoting is a summarising technique to rearrange the rows and columns in a report so as to change the view point of data in different prespective.

c) Matplotlib.pyplot.plot() and matplotlib.pyplot.scatter()

d) import numpy as n

x=n.numpy(1,100,10)

print(x)

e) When we create the dataframe object it get the row numbers and columns labels automatically but if we want to change the row numbers and column labels we can do so with help of reindexing.

The methods used in reindexing are:

Rename(),reindex() and reindex_like()

f) We can create the chart by showing different height bars by bar chart. Bar chart is a graphical representation of data using bars which is of different height. It can be drawn horizontally or vertically using rectangles.

bar() function is used to create the bar chart.

g) import numpy as n

X=np.zeros(8)

X[3]=5

Print(X)

a) ii)

Negative step value means the order will start from the end of the list.

b) A:Sham will import pandas library and the version can be checked as

import pandas as p

print(pd.__version__)

OR

matplotlib is the high quality plotting library of python.

c) sort_values function is used to arrange the data in ascending or descending order.

.sort_values(by,axis=0,ascending=True, inplace=false,kind=’quicksort’, na_position=’last’)

d) Quantile are the points in the distribution which relate to the rank order of values in that distribution.

The var() function computes variance and returns unbiased variance over requested axis.

e) The syntax of accessing multiple rows is:

.loc[ : ]

Column can be accessed by:

[]

f) pivot() doesnot supports multiple entries of a row column combination

Pivot_table() function supports multiple entries for a row,column combination.

g) apply() is a series function, so it applies the given function to one row or one column of dataframe

Applymap() is an element function, so it is applies the given function to each individual element separately.

h)

1.data.loc[‘Rose’,:]

2.data.loc[[‘liliy’,’lotus’]]

3.data.loc[:,[‘count’, ‘price’]]

i) Quartiles Q1, Q2 and Q3 are three points that divide a distribution into four parts. The 4-quantiles are called quartiles. In quantile the value of distribution donot need to be multiple of 0.25 while quartiles are multiples of 0.25 .

These all are generated with quantile() function.

a) Verification is set of activities that are carried to confirm that the software correctly implements the specific functionality.

b) 1)

The waterfall model is a linear approach of software development where the software development takes place sequentially.

c) The sprint is a period of time when software development is actually done, the main motto of sprint is to create a salable product.

d) Git is a distributed version control system.

Git comes with many useful features like:

1. Automatic backup of the whole repository is taken; in case of loss of a repo it is available in other workstations too.

2. Git provides many efficient algorithms for working.

e) The various uses of use case diagrams are:

1. Specify the context of a system.

2. To take the requirements of the system.

3. Validate the system architecture

4. Used for implementation and generate test case

There are two types of use-case diagrams

1. Business use-case diagram: it is used to define a system at an abstract level.

2. System use-case diagram: it is used to define a system at implementation level.

f) As the team members are not working in the proper way and they are not saving the version to themselves which can lead to inconsistency later. Changes made by one developer in the software can be incompatible to those who are working at the same time.

Version control exists to solve this problem, and within easy reach of the developer. Version control helps team to solve the problem by not creating inconsistency and keeping the track of the changes made by an individual.

g) An actor is a person or thing, which are outside the system and are involved in a task. The use case diagram of an airport check-in and security scheme is given below:

a) An HTTP Get Request means to receive information from web server by using a given URL over web..

b) The syntax of CREATE TABLE is:

Create table < table-name >
(< column name >< data type >[(< size >)],
< columnname >< data type >[(< size >)…..])

c) The set of one or more attribute which uniquely identify the tuple within the relation is known as primary key.

d) CSV stands for “comma-separated values”.

e) NOT NULL, DEFAULT, UNIQUE, CHECK, Primary key, Foreign Key are some of the constraints that are applied to table column.

f) DDL: Data Definition Language is used to define the data structure. The statements included in DDL are: create, alter, drop, truncate, comment and rename.

DML : Data Manipulation Language is used to manage data within schema object. The statements included in it are: select, insert, update, delete and merge.

DCL: Data Control Language to control the access to data stored in a database. The statements included in it are: Grant and revoke.

g)

i) INSERT INTO Employee

VALUES ( 5, ‘TIA’, ‘Model Town’ , ‘MATHS’)

ii) select EMP_ID and E_Name from Employee

iii) UPDATE Employee SET E_Address=MALL ROAD GUJRAT where Emp_ID=2

h) SQL Data type defines the value type that can be stored in a table column. For example if we want to store the number in a table we can store it as int data type.

The main of data types are:

1. Best usage of storage space

2. Represent all possible values

3. Improve data integrity

a) Plagiarism is stealing someone else’s work and representing it as our own work without giving credit to creator.

b) Open source software is the one which is released under license, in which we can change and distribute the software to anyone but open source software is not free.

c) Credit card fraud includes stealing of credit card, unauthorized and illegal use of credit card.

d) Secure data transmission means that applying the safeguards so that data travels safely to its target, without being accessed by any other person.

The various techniques applied to the data are:

1. SSL secure data transmission

2. Data encryption

3. Using safe protocols

e) Different tools which are assisting student with disability are:

1. Talking word processor

2. Screen readers

3. Conversation of local language to braille

4. Eye tracking mouse

f) Crowd sourcing refers to the obtaining the contribution from the crowd in form of services, content or ideas from online community.

The main advantages of crowd sourcing include:

1. Innovative ideas

2. Sharing of ideas

3. Cost saving

4. Increased efficiency.