**Teachers and Examiners** (CBSESkillEduction) collaborated to create the **CBSE Class 11 Getting Started with Python Solutions.** All the important Information are taken from the **NCERT** Textbook ** Computer Science (083) class 11**.

**Contents**show

## CBSE Class 11 Getting Started with Python Solutions

**1. Which of the following identifier names are invalid and why?**

i. | Serial_no. | v. | Total_Marks |

ii. | 1st_Room | vi. | total-Marks |

iii. | Hundred$ | vii. | _Percentage |

iv. | Total Marks | viii. | True |

**Answer – **

Invalid Identifier | Valid/ Invalid | Why |
---|---|---|

Serial_no. | Invalid | Python Identifier can contain underscore (_), but (.) is not allowed. |

1st_Room | Invalid | Identifier cannot start with a number. |

Hundred$ | Invalid | Python Identifier can contain underscore but other special character like ( !, @, #, $, % etc. ) are not allowed. |

Total Marks | Invalid | Space in also not allowed in Python identifier. |

total-Marks | Invalid | (-) hyphen is not allowed in Python identifier. |

_Percentage | Valid | ( _ ) Underscore is allowed in Python identifier. |

True | Invalid | Keyword is not allowed as Identifier |

**2. Write the corresponding Python assignment statements:a) Assign 10 to variable length and 20 to variable breadth.b) Assign the average of values of variables length and breadth to a variable sum.c) Assign a list containing strings ‘Paper’, ‘Gel Pen’, and ‘Eraser’ to a variable stationery.d) Assign the strings ‘Mohandas’, ‘Karamchand’, and ‘Gandhi’ to variables first, middle and last.e) Assign the concatenated value of string variables first, middle and last to variable fullname. Make sure to incorporate blank spaces appropriately between different parts of names.**

**Answer – **

a) length = 10, breadth = 20 or length, breadth = 10, 20

b) sum=(length + breadth) / 2

c) stationery = [ ‘Paper’ , ‘Gel Pen’ , ‘Eraser’ ]

d) first = ‘Mohandas’ , middle = ‘Karamchand’ , last = ‘Gandhi’

e) fullname = first + ” ” + middle + ” ” + last

**3. Write logical expressions corresponding to the following statements in Python and evaluate the expressions (assuming variables num1, num2, num3, first, middle, last are already having meaningful values):a) The sum of 20 and –10 is less than 12.b) num3 is not more than 24.c) 6.75 is between the values of integers num1 and num2.d) The string ‘middle’ is larger than the string ‘first’ and smaller than the string ‘last’.e) List Stationery is empty.**

**Answer – **

a) ( 20 + ( – 10 )) < 12

b) num3 <= 24 or not(num3 > 24)

c) (6.75 >= num1) and (6.75 <= num2)

d) (middle > first) and (middle < last)

e) len(Stationery) == 0

**4. Add a pair of parentheses to each expression so that it evaluates to True.a) 0 == 1 == 2b) 2 + 3 == 4 + 5 == 7c) 1 < -1 == 3 > 4**

**Answer – **

a) ( 0 == (1==2))

b) (2 + (3 == 4) + 5) == 7

c) (1 < -1) == (3 > 4 )

**5. Write the output of the following:a) num1 = 4num2 = num1 + 1num1 = 2print (num1, num2)b) num1, num2 = 2, 6num1, num2 = num2, num1 + 2print (num1, num2)c) num1, num2 = 2, 3num3, num2 = num1, num3 + 1print (num1, num2, num3)**

**Answer – **

a) 2, 5

b) 6, 4

c) Error (IndentationError: unexpected indent num3)

**6. Which data type will be used to represent the following data values and why?a) Number of months in a yearb) Resident of Delhi or notc) Mobile numberd) Pocket moneye) Volume of a spheref) Perimeter of a squareg) Name of the studenth) Address of the student**

**Answer –**

Data Values | Data Type | Why |
---|---|---|

a) Number of months in a year | Integer | Number can be store in Integer data type |

b) Resident of Delhi or not | Boolean | The result can be store in true or false |

c) Mobile number | Integer/ String | You can add mobile number in both data type |

d) Pocket money | Float | The money can be calculated in the decimal point |

e) Volume of a sphere | Float | The volume can be calculated in the decimal point |

f) Perimeter of a square | Float | The perimeter can be calculated in the decimal point |

g) Name of the student | String | Name contain characters |

h) Address of the student | String | Address contain characters, special symbol, numbers etc. |

**7. Give the output of the following when num1 = 4, num2 = 3, num3 = 2a) num1 += num2 + num3print (num1)b) num1 = num1 ** (num2 + num3)print (num1)c) num1 **= num2 + num3d) num1 = ‘5’ + ‘5’print(num1)e) print(4.00/(2.0+2.0))f) num1 = 2+9*((3*12)-8)/10print(num1)g) num1 = 24 // 4 // 2print(num1)h) num1 = float(10)print (num1)i) num1 = int(‘3.14’)print (num1)j) print(‘Bye’ == ‘BYE’)k) print(10 != 9 and 20 >= 20)l) print(10 + 6 * 2 ** 2 != 9//4 -3 and 29 >= 29/9)m) print(5 % 10 + 10 < 50 and 29 <= 29)n) print((0 < 6) or (not(10 == 6) and (10<0)))**

**Answer –**

a) Output 9

b) Output 1024

c) Output 1024

d) Output 55

e) Output 1.0

f) Output 17.2

g) Output 3

h) Output 10.0

i) Error

j) Output False

k) Output True

l) Output True

m) Output True

n) Output True

**8. Categories the following as syntax error, logical error or runtime error:a) 25 / 0b) num1 = 25; num2 = 0; num1/num2**

**Answer – **

a) Runtime Error – (ZeroDivisionError: division by zero)

b) Runtime Error

**9. A dartboard of radius 10 units and the wall it is hanging on are represented using a two-dimensional coordinate system, with the board’s center at coordinate (0,0). Variables x and y store the x-coordinate and the y-coordinate of a dart that hits the dartboard. Write a Python expression using variables x and y that evaluates to True if the dart hits (is within) the dartboard, and then evaluate the expression for these dart coordinates:a) (0,0)b) (10,10)c) (6, 6)d) (7,8)**

**Answer – **

a) True

b) False

c) True

d) False

**10. Write a Python program to convert temperature in degree Celsius to degree Fahrenheit. If water boils at 100 degree C and freezes as 0 degree C, use the program to find out what is the boiling point and freezing point of water on the Fahrenheit scale.(Hint: T(°F) = T(°C) × 9/5 + 32)**

**Answer – **

# boiling – b, freezeing – f, boiling temperature – bt, freezing temperature – ft

b = 100

f = 0

bt = b * (9/5) + 32

ft = f * (9/5) + 32

print (‘ Boiling temperature in Fahrenheit’)

print (bt)

print (‘Freezing temperature in Fahrenheit’)

print (ft)

**Output **

Boiling temperature in Fahrenheit

212.0

Freezing temperature in Fahrenheit

32.0

**11. Write a Python program to calculate the amount payable if money has been lent on simple interest. Principal or money lent = P, Rate of interest = R% per annum and Time = T years. Then Simple Interest (SI) = (P x R x T)/ 100. Amount payable = Principal + SI. P, R and T are given as input to the program.**

**Answer – **

p = float(input(‘Enter principal amount – ‘))

r = float(input(‘Enter the rate of interest – ‘))

t = float(input(‘Enter the time – ‘))

si = (p * r * t)/100

rs = si + p

print(‘Total amount – ‘,rs)

**Output **

Enter principal amount – 5000

Enter the rate of interest – 6

Enter the time – 2

Total amount – 5600.0

**12. Write a program to calculate in how many days a work will be completed by three persons A, B and C together. A, B, C take x days, y days and z days respectively to do the job alone. The formula to calculate the number of days if they work together is xyz/(xy + yz + xz) days where x, y, and z are given as input to the program.**

**Answer – **

x = int(input(‘Number of days required to do the job alone by A – ‘))

y = int(input(‘Number of days required to do the job alone by B – ‘))

z = int(input(‘Number of days required to do the job alone by C – ‘))

calculate = (x * y * z) / (x*y + y*z + x*z)

days = round(calculate,2)

print(‘Total number of days to complete the work together by A, B & C – ‘, days)

**Output **

Number of days required to do the job alone by A – 10

Number of days required to do the job alone by B – 15

Number of days required to do the job alone by C – 20

Total number of days to complete the work together by A, B & C – 4.62

**13. Write a program to enter two integers and perform all arithmetic operations on them.**

**Answer – **

num1 = int(input(“Enter 1st number “))

num2 = int(input(“Enter 2nd number “))

print(“Results:-“)

print(“Addition – “,num1 + num2)

print(“Subtraction – “,num1 – num2)

print(“Multiplication – “,num1 * num2)

print(“Division – “,num1 / num2)

print(“Modulus – “, num1 % num2)

print(“Floor Division – “,num1 // num2)

print(“Exponentiation – “,num1 ** num2)

**Output**

Enter 1st number 7

Enter 2nd number 4

Results:-

Addition – 11

Subtraction – 3

Multiplication – 28

Division – 1.75

Modulus – 3

Floor Division – 1

Exponentiation – 2401

**14. Write a program to swap two numbers using a third variable.**

**Answer –**

num1 = int(input(‘Enter 1st Number ‘))

num2 = int(input(‘Enter 1st Number ‘))

temp = num1

num1 = num2

num2 = temp

print(“After Swap”)

print(“Value of num1 – “, num1)

print(“Value of num2 – “, num2)

**Output**

Enter 1st Number 6

Enter 1st Number 4

After Swap

Value of num1 – 4

Value of num2 – 6

**15. Write a program to swap two numbers without using a third variable.**

**Answer –**

num1 = int(input(‘Enter 1st Number ‘))

num2 = int(input(‘Enter 1st Number ‘))

num1 = num1 + num2

num2 = num1 – num2

num1 = num1 – num2

print(“After Swap”)

print(“Value of num1 – “, num1)

print(“Value of num2 – “, num2)

**Output**

Enter 1st Number 6

Enter 1st Number 4

After Swap

Value of num1 – 4

Value of num2 – 6

**16. Write a program to repeat the string ‘‘GOOD MORNING” n times. Here ‘n’ is an integer entered by the user.**

**Answer –**

str = “GOOD MORNING “

n = int(input(“Enter the terms – “))

if n>0:

print(str * n)

else:

print(“Enter the value more then 0”)

**Output **

Enter the terms – 5

GOOD MORNING GOOD MORNING GOOD MORNING GOOD MORNING GOOD MORNING

**17. Write a program to find average of three numbers.**

**Answer –**

a = 7

b = 8

c = 9

average = (a + b + c)/3

print(“The average of a, b and c is “,average)

**Output**

The average of a, b and c is 8.0

**18. The volume of a sphere with radius r is 4/3πr3. Write a Python program to find the volume of spheres with radius 7cm, 12cm, 16cm, respectively.**

**Answer – **

r1 = 7

r2 = 12

r3 = 16

print(“Volume of Sphere when radius is 7cm “, round((4/3*22/7*r1**3),2))

print(“Volume of Sphere when radius is 12cm “, round((4/3*22/7*r2**3),2))

print(“Volume of Sphere when radius is 16cm “, round((4/3*22/7*r3**3),2))

**Output**

Volume of Sphere when radius is 7cm 1437.33

Volume of Sphere when radius is 12cm 7241.14

Volume of Sphere when radius is 16cm 17164.19

**19. Write a program that asks the user to enter their name and age. Print a message addressed to the user that tells the user the year in which they will turn 100 years old.**

**Answer –**

name = input(“Enter your name: “)

age = int(input(“Enter your age: “))

hundred = 2020 + (100 – age)

print(“Hello”, name,”! You will turn 100 years old in the year”, hundred)

**Output **

Enter your name: Rajesh

Enter your age: 22

Hello Rajesh ! You will turn 100 years old in the year 2098

**20. The formula E = mc2 states that the equivalent energy (E) can be calculated as the mass (m) multiplied by the speed of light (c = about 3×108 m/s) squared. Write a program that accepts the mass of an object and determines its energy.**

**Answer –**

mass = int(input(“Enter the mass “))

energy = mass * ((3 * 10 ** 8) ** 2)

print(“Energy produced by given mass is “,energy)

**Output**

Enter the mass 50

Energy produced by given mass is 4500000000000000

**21. Presume that a ladder is put upright against a wall. Let variables length and angle store the length of the ladder and the angle that it forms with the ground as it leans againstthe wall. Write a Python program to compute the height reached by the ladder on the wall for the following values of length and angle:a) 16 feet and 75 degreesb) 20 feet and 0 degreesc) 24 feet and 45 degreesd) 24 feet and 80 degrees**

**Answer – **

import math

length = int(input(“Enter the length of ladder – “))

degrees = int(input(“Enter the angle in degree – “))

rad = math.radians(degrees)

sin = math.sin(rad)

height = round(length * sin,2)

print(“Height reached by ladder”, height)

**Output **

Enter the length of ladder – 20

Enter the angle in degree – 70

Height reached by ladder 18.79

##### Computer Science Class 11 Notes

**Unit 1 : Basic Computer Organisation****Unit 1 : Encoding Schemes and Number System****Unit 2 : Introduction to problem solving****Unit 2 : Getting Started with Python****Unit 2 : Conditional statement and Iterative statements in Python****Unit 2 : Function in Python****Unit 2 : String in Python****Unit 2 : Lists in Python****Unit 2 : Tuples in Python****Unit 2 : Dictionary in Python****Unit 3 : Society, Law and Ethics**

##### Computer Science Class 11 MCQ

**Unit 1 : Basic Computer Organisation****Unit 1 : Encoding Schemes and Number System****Unit 2 : Introduction to problem solving****Unit 2 : Getting Started with Python****Unit 2 : Conditional statement and Iterative statements in Python****Unit 2 : Function in Python****Unit 2 : String in Python****Unit 2 : Lists in Python****Unit 2 : Tuples in Python****Unit 2 : Dictionary in Python****Unit 3 : Society, Law and Ethics**

##### Computer Science Class 11 NCERT Solutions

**Unit 1 : Basic Computer Organisation****Unit 1 : Encoding Schemes and Number System****Unit 2 : Introduction to problem solving****Unit 2 : Getting Started with Python****Unit 2 : Conditional statement and Iterative statements in Python****Unit 2 : Function in Python****Unit 2 : String in Python****Unit 2 : Lists in Python****Unit 2 : Tuples and Dictionary in Python****Unit 3 : Society, Law and Ethics**