Question 1

To secure your account, whether it be an email, online bank account or any other account, it is important that we use authentication. Use your programming expertise to create a program using user defined function named login that accepts userid and password as parameters (login(uid,pwd)) that displays a message “account blocked” in case of three wrong attempts. The login is successful if the user enters user ID as "ADMIN" and password as "St0rE@1". On successful login, display a message “login successful”.

Accepted Answer

Solution:

We need to create a function named login(uid, pwd) which checks the userid and password. The function should allow three attempts. If the user enters the correct userid "ADMIN" and password "St0rE@1", display "login successful". If three wrong attempts are made, display "account blocked".

Sample Python code:

```python
attempts = 0

while attempts < 3:
    uid = input("Enter user ID: ")
    pwd = input("Enter password: ")
    if uid == "ADMIN" and pwd == "St0rE@1":
        print("login successful")
        break
    else:
        print("Wrong credentials")
        attempts += 1
else:
    print("account blocked")
```

Explanation:
- The program uses a loop to allow up to three attempts.
- If correct credentials are entered, it prints "login successful" and breaks the loop.
- If three wrong attempts are made, it prints "account blocked". — The function login(uid, pwd) checks the credentials. The program allows three attempts. On correct credentials, it prints "login successful" and exits. After three failed attempts, it prints "account blocked".

Question 2

XYZ store plans to give festival discount to its customers. The store management has decided to give discount on the following criteria: Shopping Amount Discount Offered >=500 and <1000 5% >=1000 and <2000 8% >=2000 10% An additional discount of 5% is given to customers who are the members of the store. Create a program using user defined function that accepts the shopping amount as a parameter and calculates discount and net amount payable on the basis of the following conditions: Net Payable Amount = Total Shopping Amount – Discount.

Accepted Answer

Solution: We need to write a function that accepts shopping amount and membership status, calculates the discount based on the criteria, and returns the net payable amount. Sample Python code: ```python def calculate_discount(amount, is_member): discount = 0 if amount >= 500 and amount < 1000: discount = 0.05 * amount elif amount >= 1000 and amount < 2000: discount = 0.08 * amount elif amount >= 2000: discount = 0.10 * amount if is_member: discount += 0.05 * amount net_payable = amount - discount return discount, net_payable # Example usage amount = float(input("Enter shopping amount: ")) member_input = input("Are you a member? (yes/no): ") is_member = member_input.lower() == 'yes' discount, net_amount = calculate_discount(amount, is_member) print(f"Discount: {discount}") print(f"Net amount payable: {net_amount}") ``` Explanation: - The function checks the amount range and applies the corresponding discount. - If the customer is a member, an additional 5% discount is added. - Finally, net payable amount is calculated by subtracting discount from total amount. — The function calculates discount based on amount slabs and membership. It returns discount and net payable amount. The program then displays these values.

Question 3

‘Play and learn’ strategy helps toddlers understand concepts in a fun way. Being a senior student you have taken responsibility to develop a program using user defined functions to help children master two and three-letter words using English alphabets and addition of single digit numbers. Make sure that you perform a careful analysis of the type of questions that can be included as per the age and curriculum.

Accepted Answer

Solution:

This is an open-ended question requiring the creation of a program with user defined functions to help toddlers learn two and three-letter words and addition of single digit numbers.

Approach:
- Create functions to display two and three-letter words.
- Create functions to generate simple addition problems with single digit numbers.
- Use loops and input to interact with children.

Sample outline:

```python
def display_two_letter_words():
    words = ['an', 'at', 'in', 'on', 'up']
    for word in words:
        print(word)

def display_three_letter_words():
    words = ['cat', 'dog', 'sun', 'hat', 'bat']
    for word in words:
        print(word)

def addition_quiz():
    import random
    a = random.randint(0,9)
    b = random.randint(0,9)
    print(f"What is {a} + {b}?")
    answer = int(input())
    if answer == a + b:
        print("Correct!")
    else:
        print(f"Incorrect. The answer is {a + b}")

# Example usage
print("Two letter words:")
display_two_letter_words()
print("Three letter words:")
display_three_letter_words()
addition_quiz()
```

Explanation:
- The functions help children learn words and practice addition interactively.
- The program can be extended with more words and questions as per curriculum. — The program uses user defined functions to display words and quiz addition. It is designed to be interactive and age-appropriate.

Question 4

Take a look at the series below:
1, 1, 2, 3, 5, 8, 13, 21, 34, 55…
To form the pattern, start by writing 1 and 1. Add them together to get 2. Add the last two numbers: 1+2 = 3. Continue adding the previous two numbers to find the next number in the series. These numbers make up the famed Fibonacci sequence: previous two numbers are added to get the immediate new number.

Accepted Answer

Solution:

This question explains the Fibonacci sequence and expects a program or explanation to generate the sequence.

Sample Python code to generate first n Fibonacci numbers:

```python
def fibonacci(n):
    fib_series = [1, 1]
    while len(fib_series) < n:
        next_num = fib_series[-1] + fib_series[-2]
        fib_series.append(next_num)
    return fib_series[:n]

# Example usage
n = 10
print(fibonacci(n))
```

Explanation:
- Start with 1 and 1.
- Each next number is sum of previous two.
- The function returns the first n numbers of the Fibonacci sequence. — The Fibonacci sequence is generated by adding the last two numbers to get the next. The program implements this logic to generate the sequence.

Question 5

Create a menu driven program using user defined functions to implement a calculator that performs the following:
a) Basic arithmetic operations(+,-,*,/)
b) log (x), sin(x), cos(x)

Accepted Answer

Solution:

We need to create a menu driven calculator program with user defined functions for basic arithmetic and some trigonometric/logarithmic functions.

Sample Python code:

```python
import math

def add(x, y):
    return x + y

def subtract(x, y):
    return x - y

def multiply(x, y):
    return x * y

def divide(x, y):
    if y != 0:
        return x / y
    else:
        return 'Error: Division by zero'

def logarithm(x):
    if x > 0:
        return math.log10(x)
    else:
        return 'Error: log undefined for non-positive numbers'

def sine(x):
    return math.sin(math.radians(x))

def cosine(x):
    return math.cos(math.radians(x))

while True:
    print("Menu:")
    print("1. Add")
    print("2. Subtract")
    print("3. Multiply")
    print("4. Divide")
    print("5. log(x)")
    print("6. sin(x)")
    print("7. cos(x)")
    print("8. Exit")
    choice = input("Enter choice: ")

if choice == '8':
        break

if choice in ['1','2','3','4']:
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))

if choice == '1':
            print("Result:", add(num1, num2))
        elif choice == '2':
            print("Result:", subtract(num1, num2))
        elif choice == '3':
            print("Result:", multiply(num1, num2))
        elif choice == '4':
            print("Result:", divide(num1, num2))

elif choice in ['5','6','7']:
        num = float(input("Enter number: "))
        if choice == '5':
            print("Result:", logarithm(num))
        elif choice == '6':
            print("Result:", sine(num))
        elif choice == '7':
            print("Result:", cosine(num))
    else:
        print("Invalid choice")
```

Explanation:
- The program uses functions for each operation.
- It displays a menu and performs the selected operation.
- For trigonometric functions, input is taken in degrees and converted to radians. — The program implements a menu driven calculator with user defined functions for arithmetic and trigonometric/logarithmic operations.

Question 6

Write a program to check the divisibility of a number by 7 that is passed as a parameter to the user defined function.

Accepted Answer

Solution:

Create a function that accepts a number and checks if it is divisible by 7.

Sample Python code:

```python
def is_divisible_by_7(num):
    if num % 7 == 0:
        return True
    else:
        return False

# Example usage
number = int(input("Enter a number: "))
if is_divisible_by_7(number):
    print(f"{number} is divisible by 7")
else:
    print(f"{number} is not divisible by 7")
```

Explanation:
- The function uses modulus operator to check divisibility.
- Returns True if divisible, else False. — The function checks if the remainder when divided by 7 is zero. If yes, number is divisible by 7.

Question 7

Write a program that uses a user defined function that accepts name and gender (as M for Male, F for Female) and prefixes Mr/Ms on the basis of the gender.

Accepted Answer

Solution:

Create a function that accepts name and gender and returns the name with prefix Mr or Ms.

Sample Python code:

```python
def prefix_name(name, gender):
    if gender.upper() == 'M':
        return "Mr. " + name
    elif gender.upper() == 'F':
        return "Ms. " + name
    else:
        return name

# Example usage
name = input("Enter name: ")
gender = input("Enter gender (M/F): ")
print(prefix_name(name, gender))
```

Explanation:
- The function checks gender and prefixes accordingly.
- If gender is not M or F, returns name as is. — The function prefixes Mr or Ms based on gender input and returns the full name.

Question 8

Write a program that has a user defined function to accept the coefficients of a quadratic equation in variables and calculates its determinant. For example : if the coefficients are stored in the variables a,b,c then calculate determinant as b2-4ac. Write the appropriate condition to check determinants on positive, zero and negative and output appropriate result.

Accepted Answer

Solution:

Create a function that accepts coefficients a, b, c and calculates determinant (discriminant) = b^2 - 4ac. Then check if determinant is positive, zero or negative and print the nature of roots.

Sample Python code:

```python
def determinant(a, b, c):
    det = b**2 - 4*a*c
    if det > 0:
        result = "Roots are real and distinct"
    elif det == 0:
        result = "Roots are real and equal"
    else:
        result = "Roots are complex"
    return det, result

# Example usage
a = float(input("Enter coefficient a: "))
b = float(input("Enter coefficient b: "))
c = float(input("Enter coefficient c: "))
det, nature = determinant(a, b, c)
print(f"Determinant: {det}")
print(nature)
```

Explanation:
- The function calculates determinant.
- Based on determinant value, it determines the nature of roots. — Determinant is calculated using formula b^2 - 4ac. Positive determinant means real distinct roots, zero means real equal roots, negative means complex roots.

Question 9

ABC School has allotted unique token IDs from (1 to 600) to all the parents for facilitating a lucky draw on the day of their Annual day function. The winner would receive a special prize. Write a program using Python that helps to automate the task.(Hint: use random module)

Accepted Answer

Solution:

Use Python's random module to select a random token ID between 1 and 600.

Sample Python code:

```python
import random

def lucky_draw():
    winner = random.randint(1, 600)
    return winner

print(f"The winner token ID is: {lucky_draw()}")
```

Explanation:
- random.randint(1,600) generates a random integer between 1 and 600 inclusive.
- This simulates the lucky draw winner selection. — The program uses random.randint to select a winner token ID between 1 and 600.

Question 10

Write a program that implements a user defined function that accepts Principal Amount, Rate, Time, Number of Times the interest is compounded to calculate and displays compound interest. (Hint: CI=P*(1+r/n)nt)

Accepted Answer

Solution:

Create a function to calculate compound interest using formula:
CI = P * (1 + r/n)^(n*t) - P

where P = principal, r = rate (in decimal), n = number of times compounded per year, t = time in years.

Sample Python code:

```python
def compound_interest(P, r, t, n):
    amount = P * (1 + r/n)**(n*t)
    CI = amount - P
    return CI

# Example usage
P = float(input("Enter principal amount: "))
r = float(input("Enter annual rate of interest (in %): ")) / 100
t = float(input("Enter time in years: "))
n = int(input("Enter number of times interest compounded per year: "))
ci = compound_interest(P, r, t, n)
print(f"Compound Interest is: {ci}")
```

Explanation:
- Convert rate percentage to decimal.
- Calculate amount using formula.
- Compound interest is amount minus principal. — The function calculates compound interest using the formula CI = P*(1 + r/n)^(nt) - P.

Question 11

Write a program that has a user defined function to accept 2 numbers as parameters, if number 1 is less than number 2 then numbers are swapped and returned, i.e., number 2 is returned in place of number1 and number 1 is reformed in place of number 2, otherwise the same order is returned.

Accepted Answer

Solution:

Create a function that accepts two numbers, swaps them if first is less than second, else returns as is.

Sample Python code:

```python
def swap_if_less(num1, num2):
    if num1 < num2:
        return num2, num1
    else:
        return num1, num2

# Example usage
n1 = float(input("Enter first number: "))
n2 = float(input("Enter second number: "))
new_n1, new_n2 = swap_if_less(n1, n2)
print(f"Numbers after processing: {new_n1}, {new_n2}")
```

Explanation:
- Function checks if num1 < num2.
- If yes, returns swapped values.
- Else returns original order. — The function swaps numbers if first is less than second, else returns them unchanged.

Question 12

Write a program that contains user defined functions to calculate area, perimeter or surface area whichever is applicable for various shapes like square, rectangle, triangle, circle and cylinder. The user defined functions should accept the values for calculation as parameters and the calculated value should be returned. Import the module and use the appropriate functions.

Accepted Answer

Solution:

Create functions for each shape to calculate area, perimeter or surface area as applicable.

Sample Python code:

```python
import math

def area_square(side):
    return side * side

def perimeter_square(side):
    return 4 * side

def area_rectangle(length, breadth):
    return length * breadth

def perimeter_rectangle(length, breadth):
    return 2 * (length + breadth)

def area_triangle(base, height):
    return 0.5 * base * height

def perimeter_triangle(a, b, c):
    return a + b + c

def area_circle(radius):
    return math.pi * radius * radius

def circumference_circle(radius):
    return 2 * math.pi * radius

def surface_area_cylinder(radius, height):
    return 2 * math.pi * radius * (radius + height)

# Example usage
print("Area of square with side 5:", area_square(5))
print("Surface area of cylinder with radius 3 and height 7:", surface_area_cylinder(3,7))
```

Explanation:
- Functions accept parameters and return calculated values.
- math module is imported for pi.
- User can call appropriate function as needed. — Functions calculate area, perimeter or surface area for given shapes using parameters and return the result.

Question 13

Write a program that creates a GK quiz consisting of any five questions of your choice. The questions should be displayed randomly. Create a user defined function score() to calculate the score of the quiz and another user defined function remark (scorevalue) that accepts the final score to display remarks as follows:
Marks Remarks
5 Outstanding
4 Excellent
3 Good
2 Read more to score more
1 Needs to take interest
0 General knowledge will always help you. Take it seriously.

Accepted Answer

Solution:

Create a quiz program with 5 questions displayed randomly. Use functions score() to calculate score and remark(scorevalue) to display remarks.

Sample Python code:

```python
import random

questions = [
    ("Capital of India?", "New Delhi"),
    ("Largest planet?", "Jupiter"),
    ("Author of Harry Potter?", "J.K. Rowling"),
    ("Speed of light in vacuum (km/s)?", "300000"),
    ("Chemical symbol of water?", "H2O")
]

random.shuffle(questions)

score_value = 0

def score():
    global score_value
    for q, ans in questions:
        user_ans = input(q + " ")
        if user_ans.strip().lower() == ans.lower():
            score_value += 1

def remark(scorevalue):
    remarks = {
        5: "Outstanding",
        4: "Excellent",
        3: "Good",
        2: "Read more to score more",
        1: "Needs to take interest",
        0: "General knowledge will always help you. Take it seriously."
    }
    print(remarks.get(scorevalue, ""))

score()
print(f"Your score is: {score_value}")
remark(score_value)
```

Explanation:
- Questions are shuffled randomly.
- score() function calculates correct answers.
- remark() function displays remarks based on score. — The program quizzes user with 5 random questions, calculates score, and displays remarks accordingly.

Question 14

7.1 Convert all the functionality in Chapter 5 and 6 using user defined functions.

Accepted Answer

Solution:

This is a case study-based question requiring the conversion of all functionalities from Chapters 5 and 6 into user defined functions.

Approach:
- Identify all functionalities from Chapters 5 and 6.
- Write functions encapsulating each functionality.
- Replace existing code with function calls.

Since the question is broad, the solution involves modular programming and function creation as per the previous chapters' content.

Example:
If Chapter 5 had student data input, create a function input_student_data().
If Chapter 6 had attendance calculation, create a function calculate_attendance().

Explanation:
- Modular programming improves code readability and reusability.
- Functions help organize code logically. — Convert all previous chapter functionalities into user defined functions for modularity and reusability.

Question 15

7.2 Add another user defined function to the above menu to check if the student has short attendance or not. The function should accept total number of working days in a month and check if the student is a defaulter by calculating his or her attendance using the formula: Count of days the student was present or the total number of working days. In case the attendance calculated is less than 78%, the function should return 1 indicating short attendance otherwise the function should return 0 indicating attendance is not short.

Accepted Answer

Solution:

Create a function check_attendance(present_days, total_days) that calculates attendance percentage and returns 1 if attendance < 78%, else 0.

Sample Python code:

```python
def check_attendance(present_days, total_days):
    attendance_percentage = (present_days / total_days) * 100
    if attendance_percentage < 78:
        return 1  # short attendance
    else:
        return 0  # attendance not short

# Example usage
present = int(input("Enter number of days student was present: "))
total = int(input("Enter total number of working days: "))
result = check_attendance(present, total)
if result == 1:
    print("Student has short attendance")
else:
    print("Attendance is sufficient")
```

Explanation:
- Attendance percentage is calculated.
- Function returns 1 if less than 78%, else 0. — The function calculates attendance percentage and returns 1 if below 78%, else 0.

Functions

Functions — Study Notes

Introduction

Functions: Definition and Calling

Parameters and Arguments

Practice Questions — Functions

All 11 Chapters in Computer Science