SET-A KENDRIYA VIDYALAYA SANGATHAN, AGRA REGION PRE … · 2019. 12. 17. · Agile software...

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SET-A

KENDRIYA VIDYALAYA SANGATHAN, AGRA REGION

PRE BOARD EXAMINAION 2019-20

CLASS XII INFORMATICS PRACTICES(065)

Time allowed: 3 hours Max. Marks: 70

MARKING SCHEME

Section A

Answer the following questions :

1 a) Find the output of following program

import numpy as np

d=np.array([100,200,300,400,500,600,700])

print(d[-6:-2])

1

Ans : [200 300 400 500] (1 mark for correct output)

b) Point out the incorrect statement:

A. Both Series and ndarrays can be passed as arguments to Numpy functions. B. The major difference between Series and ndarray is that the data is arranged based on label in Series, when Series is operated on.

C. A DataFrame is similar to a fixed-size dict because you can use the index labels to get and set values.

D. None of the above.

1

Ans : Option C (1 mark for correct Option C )

c) Fill in the blank with appropriate numpy method to calculate and print the variance of

an array.

import numpy as np data=np.array([10,20,30,40,50,60])

print(np. (data,ddof=0)

OR

Create an ndarray with values ranging from 10 to 40 each specified with a

difference of 3.

1

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Ans : print(np.var(data,ddof=0)) (1 mark for appropriate function var)

OR

import numpy as np (1 mark for appropriate arrange function)

Z=np.arange(10,40,3)

d) Explain the use of vsplit( ) function with syntax and example. 2

Ans : numpy.vsplit is a special case of split() function where axis is 1 indicating a vertical

split regardless of the dimension of the input array.

a = np.arange(16).reshape(4,4)

b = np.vsplit(a,2)

print b

(1 mark for correct use of vsplit( ), 1 mark for correct example.)

e) Write a Python programming code to display a bar chart of the popularity of

programming Languages.

Sample data:

Programming languages: Java, Python, PHP, JavaScript, C#, C++

Popularity: 22.2, 17.6, 8.8, 8, 7.7, 6.7

2

Ans : import matplotlib.pyplot as plt

x = ['Java', 'Python', 'PHP', 'JavaScript', 'C#', 'C++']

popularity = [22.2, 17.6, 8.8, 8, 7.7, 6.7]

x_pos = [i for i, _ in enumerate(x)]

plt.bar(x_pos, popularity)

(1/2 mark for each line of code) ( 2 mark for correct code or similar code)

f) What is series ?Explain with the help of an example.

2

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Ans : Pandas Series is a one dimensional labeled array capable of holding data of any

type(integer,string,float,python objects etc)

The axis labels are collectively called index.Example

import pandas as pd

data=pd.Series([1,2,3,4,5])

print(data)

(g) Write a Numpy program to find out smallest and sum of array elements

0,1,2,3,4,5,6,7,8,9.

OR

Write a python programming code to display and create a 8x8 ndarray and fill it

with a checkerboard pattern i.e. 0 and 1 at alternative positions.

3

Ans: import numpy as np

arr=np.array([0,1,2,3,4,5,6,7,8,9])#s1

a=arr.min() #s2

b=arr.sum() #s3

print(a)

print(b)

OR

import numpy as np

arr=np.array([0,1,2,3,4,5,6,7,8,9])#s1

print(::-1)#s2

print(a.T)#s3

3

marks

for

correc

t code

OR

import numpy as np

c=np.zeros((8,8),dtype=int)

c[1::2,::3]=1

c[::2,1::2]=1

Print(c)


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2 a) Which Pandas Dataframe function is used to get list from DataFrame column headers:

A. print(list(df.columns.values))

B. print(list(df.rows.values))

C. print(list(df.columns.index))

D. print(list(df.head))

1

Ans : OPTION A

b) Find the output of following program:

import pandas as pd

df = pd.DataFrame([[1, 2], [4, 5], [7, 8]],

index=['cobra', 'viper', 'sidewinder'],

columns=['max_speed', 'shield'])

print(df.loc['cobra', 'shield'])

1

Ans : 2

c) Explain Pandas iterrow(). Give example. 1

iterrows() − iterate over the rows as (index,series) pairs. Example :

df = pd.DataFrame(np.random.randn(4,3),columns = ['col1','col2','col3'])

for row_index,row in df.iterrows():

print row_index,row

d) Which method is used to compare two dataframe? 1

Ans : equals()

e) How does pivot-table differ() from pivot()? 2

Ans : pivot() is used for pivoting without aggregation. Therefor, it can‘t deal with duplicate

values for one index/column pair. pivot_table is a generalization of pivot that can handle

duplicate values for one pivoted index/column pair. Specifically, you can give

pivot_table a list of aggregation functions using keyword argument aggfunc. The default

aggfunc of pivot_table is numpy.mean. ( 2 mark for correct answer.)

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f) Write a python code to create a dataframe as per given structure in the figure.

Country Rank

0 Russia 121

1 Colombia 40

2 Chile 100

3 Equador 130

4 Nigeria 11

2

OR

Write a small python code to create a dataframe with headings (sid, age) from the list given

below.

[ [‘S1’,20],[‘S2’,30],[‘S3’,40], [‘S4’,50] ]

Ans : import pandas as pd

data = pd.DataFrame({'Country': ['Russia','Colombia','Chile','Equador','Nigeria'],

'Rank':[121,40,100,130,11]}) ( 2 mark for correct answer.)

print(data)

OR

( 2 mark for correct answer.)

import pandas as pd

df1=pd.dataframe([‘S1’,20],[‘S2’,30] ],columns=[‘id’,’age’] ]

df2= pd.dataframe([‘S3’,40],[‘S4’,50] ],columns=[‘id’,’age’] ]

df1.=df1.append(df2)

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g) Consider the following dataframe, and answer the questions given below:

import pandas as pd

data = pd.DataFrame(np.arange(12).reshape((3, 4)),

index=['Ohio', 'Colorado', 'New York'],columns=['one', 'two', 'three', 'four'])

(i) Write the code to rename column name from 'Ohio' to 'SanF'.

(ii) Write the code to find mean value from above dataframedf over the

index and column axis. (Skip NaN value).

(iii) Use sum() function to find the sum of all the values over the index axis.

OR

Consider the following dataframe df and answer the questions given below:

import pandas as pd

df = pd.DataFrame([[10, 20, 30, 40], [7, 14, 21, 28], [55, 15, 8, 12],

[15, 14, 1, 8], [7, 1, 1, 8], [5, 4, 9, 2]],

columns=['Apple', 'Orange', 'Banana', 'Pear'],

index=['Basket1', 'Basket2', 'Basket3', 'Basket4', 'Basket5', 'Basket6'] )

i) Write a command to calculate minimum value for each of the columns

ii) Write a command to calculate maximum value for each of the rows

iii) Write a command to complete mean, mode and median

3

Ans : (i) data.rename(index = {'Ohio':'SanF'},

columns={'one':'one_p','two':'two_p'},inplace=True)

(ii) print(df.mean(axis = 1, skipna = True))

print(df.mean(axis = 0, skipna = True))

(iii) print(df.sum(axis = 1, skipna = True) ( 1 marks each,3 mark for correct answer.)

OR

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print("\n----------- Minimum -----------\n")

print(df[['Apple', 'Orange', 'Banana', 'Pear']].min())

print("\n----------- Maximum -----------\n")

print(df[['Basket1', 'Basket2', 'Basket3', 'Basket4',

'Basket5', 'Basket6']].max())

print("\n----------- Calculate Mean -----------\n")

print(df.mean())

print("\n----------- Calculate Median -----------\n")

print(df.median())

print("\n----------- Calculate Mode -----------\n")

print(df.mode())

( 1 marks each,3 mark for correct answer.)

h) Consider the following dataframe named carPriceDf , carsHorsepowerDf

and answer the questions given below:

Car_Price = {'Company': ['Toyota', 'Honda', 'BMV', 'Audi'], 'Price': [23845, 17995,

135925 , 71400]}

carPriceDf = pd.DataFrame.from_dict(Car_Price)

car_Horsepower = {'Company': ['Toyota', 'Honda', 'BMV', 'Audi'], 'horsepower': [141, 80,

182 , 160]}

carsHorsepowerDf = pd.DataFrame.from_dict(car_Horsepower)

Write the commands to do the following operations on the dataframes :

(i) To add dataframes carPriceDf and carsHorsepowerDf

(ii) To subtract carsHorsepowerDf from carPriceDf

(iii) To Merge two data frames, and append second data frame as a new column

to the first data frame.

3

Ans : (i) print((pd.concat([carPriceDf , carsHorsepowerDf]))

(ii) print(carPriceDf.subtract(carsHorsepowerDf))

(iii) carsDf = pd.merge(carPriceDf, carsHorsepowerDf, on="Company")

print(carsDf) ( 1 marks each,3 mark for correct answer.)

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i) Find the output of the following code:

import pandas as pd

import numpy as np

s1 = pd.Series(['100', '200', 'python', '300.12', '400'])

s2 = pd.Series(['10', '20', 'php', '30.12', '40'])

print("Data Series:")

print(s1)

print(s2)

df = pd.concat([s1, s2], axis=1)

print("New DataFrame combining two series:")

print(df)

4

Ans : Data Series: 0 100

1 200

2 python

3 300.12

4 400

0 10

1 20

2 php

3 30.12

4 40

New DataFrame combining two series:

0 1

0 100 10

1 200 20

2 python php

3 300.12 30.12

4 400 40

( 01 mark for correct output of print(s1), 01 mark for correct output of print(s2),

02 mark for correct output of print(df) )

Section B


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3 a) Which of the following is NOT the phase consisting on spiral model of software

development.

A) Planning

B) Design

C) Engineering

D) Risk-Analysis

1

Ans : Option B

b) is the process of checkinq the developed software for its correctness and error free working

A. Specification

B. Desiqn/Implementation

C. Validation/Testing

D. Evolution

1

Ans : Option C

c) Write down any one benefit of version control. 1

Ans : merge all the changes into a common version. (1 mark for correct answer)

d) What are differences between commit/update and push/pull requests ?

2

Ans : Commit refers to updating the file in local repository on a distributed version control system.

Push refers to updating the file in remote repository on a distributed version control

(2 mark for correct answer)

e) Explain waterfall model. Also mention one advantage and one disadvantage of waterfall

software process.

OR

Explain spiral delivery model. Also mention one advantage and one disadvantage of spiral

delivery

3

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Ans : The water fall model is a linear and sequential approach of software development where software

develops systematically from one phase to another in a downward fashion. The model is divided into

different phases and the output of one phase is used as input of next phase.

The phases are as follows:

1. Requirements specifications 2. Analysis and system design

3. Implementation and unit testing 4. Integration and system testing

5. Operation and maintenance

Advantage : Simple and easy to understand

Disadvantage : No working software till the last phase

3 marks (1 mark for explanation 1 mark for correct advantage and 1mark for correct

disadvantage)

OR

Spiral Model is a combination of a waterfall model and iterative model. Each phase in spiral

model begins with a design goal and ends with the client reviewing the progress.

Advantage- Additional functionality or changes can be done at a later stage

Cost estimation becomes easy as the prototype building is done in small fragments

Disadvantage-Risk of not meeting

3 marks (1 mark for explanation 1 mark for correct advantage and 1mark for correct

disadvantage)

f) What is agile software development? Give difference between traditional approach of

software development and agile methods.

OR

Define about scrum and pair programming used in agile software development.

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Agile software development

Agile software development refers to a group of software development methodologies based on

iterative development, where requirements and solutions evolve through collaboration between

self-organizing cross-functional teams.

Agile is a process that helps teams provide quick and unpredictable responses to the feedback they

receive on their project. It creates opportunities to assess a project's direction during

the development cycle. Teams assess the project in regular meetings called sprints or iterations.

The main difference between traditional and agile approaches is the sequence of project phases –

requirements gathering, planning, design, development, testing and UAT. In traditional development

methodologies, the sequence of the phases in which the project is developed is linear where as in

Agile, it is iterative. (2 mark for correct explanation of Agile software development

and 2 mark for difference )

OR

Scrum is an agile framework for managing knowledge work, with an emphasis on software

development, although it has wide application in other fields and is slowly starting to be explored by

traditional project teams more generally. It is designed for teams of three to nine members, who break

their work into actions that can be completed within time boxed iterations, called sprints, no longer

than one month and most commonly two weeks, then track progress and re-plan in 15-minute time

boxed stand-up meetings, called daily scrums.

Pair programming is an agile software development technique in which two programmers work

together at one workstation. One, the driver, writes code while the other, the observer or navigator

reviews each line of code as it is typed in. The two programmers switch roles frequently.

(11/2 mark for correct explanation of Scrum and 1

1/2 mark for correct explanation for Pair

programming )

g) Draw a use-case diagram for a online cab / taxi booking app.

OR

Draw a use-case diagram for a Bank ATM system.

4

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Ans :

(4 marks for correct use case diagram)

Section C


4 a) Which command is used to create a new app named OLA in Django project? 1

Ans :

python manage.py startapp OLA

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b) The COUNT function in SQL returns the number of ______________

A. Values B. Distinct values

C. Group By D. Columns

OR

Which Command is used for changing values in Mysql table

A. Alter B. Update

C. Select D. Delete

1

Ans :

Option A

OR

Update

c) Mandatory arguments required to connect any database from Python

A. Username, Password, Hostname, Database Name, Port.

B. Username, Password, Hostname

C. Username, Password, Hostname, Database Name

D. Username, Password, Database Name

1

Ans :

Option C

d) What is the name of a special control structure that facilitates the row-by-row processing of

records in the result set during Python-MySQL connectivity? 1

Ans :

Database cursor.

e) Which command is used for destroying table in mysql ? 1

Ans :

Drop

f) The doc_name column of a table hospital is given below

Doc_name Avinash Ranjeet Aman Kushagra Based on the information ,find the output of the following queries: (i)Write mysql command to display Doc_name starting with letter ‘K’ having any length. (ii) Write mysql command to display Doc_name ending with letter ‘A’ having only four character. (iii) Write mysql command to change name ‘Aman’ by new name ‘Arun’.

3

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Ans :

(i)select doc_name from hospital where doc_name like ―K%‖.

(ii) select doc_name from hospital where doc_name like ―_ _ _A‖.

(iii)Update Hospital set Doc_name=‘Arun‘ where Doc_name=‘Aman‘;

g) Observe the table ‗Club‘ given below:

Club

i. What is the cardinality and degree of the above given table?

ii. If a new column contact_no has been added and two more members have

joined the club then how these changes will affect the degree and

cardinality of the above given table.

iii. Write MySQL command to add a new column contact_no.

Member_id Member_nam

e

Address Age Fees

M001 Sumit New Delhi 20 1000

M002 Nisha Gurgaon 19 1500

M003 Niharika New Delhi 21 2100

M004 Sachin Faridabad 18 1500

3

Ans :

i. Cardinality:4

Degree: 5

(½ mark for each correct answer)

ii. Cardinality: 6

Degree: 6

(½ mark for each correct answer)

iii. Alter table Club add contact_no varchar(20);

(1 Mark Each for queries from (i) to (iii) )

h) Consider the table FLIGHT given below. Write commands in SQL for (i) to (iv) and output

for (v) to (vi). ( queries from (i) to (iii)=1 Mark Each & from (iv) to (v)= ½ Mark Each)

((i) Display details of all flights starting from Delhi.

(ii) Display details of flights that have more than 4 number of flights operating.

(iii) Display flight codes, starting place, destination, number of flights in descending order

of number of flights.

(iv)Add on column ―Remarks‖ in given table FLIGHT .

(v) SELECT MAX(NO_FLIGHTS) FROM FLIGHT;

(vi)SELECT START, COUNT(*) FROM FLIGHT GROUP BY Start;

4

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Ans :

(i)select * from flight where start=‘delhi‘;

(ii) select * from flights where no_flights>4;

(iii) select flcode, start, destination, no_flights from flight order by no_flights desc;

(iv)Alter Table Flight add Remarks varchar(20)

(v) 7

(vi) DELHI 3

MUMBAI 2

KANPUR 1

INDORE 1

(1 Mark Each for queries from (i) to (iii), ½ Mark Each for correct output )

OR

(i)In a bank,a database named PNB is created in mysql whose password is

―123‖.Reema is trying toad a new record of PNB having

details(‗E1‘,‘Meena‘,‘Delhi‘) in a PNB table.

(ii)Write the python code to read the contents of ―first.csv‖ file consisting of data from a

mysql table and print data of table on the screen in tabular form of table.

Ans.import mysql.connector

Mydb=mysql.connector.connect(host=‖localhost‖,user=‖root‖,passwd=‖123‖,

database=‖PNB‖)

mycursor=mydb.cursor()

mycursor.excute(―insert into PNB values(‗E1‘,‘Meena‘,‘Delhi‘);‖)

mydb.commit()

(ii)f=open(‗first.csv‘,‘r‘)

with f:

reader =csv.reader(f)

for row in reader:

for e in row:

print(e)

Section D


5 a) Vinod is preparing financial analysis report of its organisation. Can he copy and paste

information from the Internet for reference in his report?

1

Ans :

Yes, he can do this but only after giving the reference to all the sources, otherwise it will be

treated as copyright violation.

b) What does the term ―Intellectual Property Rights‖ covers? 1

Ans :

The term ―Intellectual Property Rights‖ covers Copyrights, Trademarks and Patents.

c) What are the environmental issues of e-waste? 1

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Ans :

E-waste, or electronic waste, is waste from all sorts of electronics ranging from computers

and mobile phones, to household electronics such as food processors, pressure cookers, etc.

The effects of improper disposal of this e-waste on the environment are little known;

however, damage to the atmosphere is one of the biggest environmental impacts of e-waste.

d) What do you understand by the term Plagiarism? Write two software used as plagiarism

checker.

2

Ans :

Plagiarism is ―copying and publication‖ of another author‘s ―language, thoughts, ideas, or

expressions‖ and the representation of them as one‘s own original work. Plagiarism is

considered academic dishonesty and a breach of journalistic ethics.

The software available for Plagiarism checker are:

(i) DupliChecker (ii) Grammarly (iii) Paperrater (iv) Plagiarisma

(1 mark for correct explanation of Plagiarism and 1 mark for two software)

(2 mark for correct answer)

e) List down some points about societal changes introduced by technology. 2

Ans :

Technology is the application of scientific knowledge to the making of tools to solve

specific problems. Technological advances such as automobiles, airplanes, radio, television,

cellular phones, computers, modems, and fax machines have brought major advances and

changes to the world. (2 mark for correct answer)

f) What do you understand by Computer ethics? OR

Explain the role of online social media campaigns, crowdsourcing and smart mobs in

society.

3

Computer ethics are a set of moral principles that govern the behaviour of a group or an

individual and regulate the use of computers. These include intellectual property rights

(such as copyrighted electronic content), privacy concerns, and how computers affect our

society. (3 mark for correct answer)

OR

Role of Social Media Campaigns:-

A social media campaign should focus around a singular business goal, whether it's on

Facebook or Instagram. Common goals for a social media campaigns include:

Getting feedback from users.

Building email marketing lists

Increasing website traffic

Crowdsourcing is the practice of engaging a ‗crowd‘ or group for a common goal — often

innovation, problem solving, or efficiency. It is powered by new technologies, social media

and web 2.0. Crowdsourcing can take place on many different levels and across various

industries.

Smart mobs, so named because each person in the group uses technology to receive

information on where to go and what to do. This ability to stay on top of current events

makes smart mobs extremely effective

3 marks (1 mark for one correct role of social media campaign, 1 mark for one correct role

of Crowdsourcing and 1 mark for one correct role of Smart mob)

role of Crowdsourcing and 1 mark for one correct role of Smart mob)

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