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Python · Classes, objects & inheritance

14 questions · 32 marks · 6 papers

Answer key

Indian Institute of Technology Madras

BS Degree Programme · Examination & Study Paper

Programming in Python

Classes, objects & inheritance

Official Paper

Examination Instructions & Guidelines

Solve on notebook/paper first before checking solutions.
MCQ: Exactly 1 option is correct. Negative marking applies.
MSQ: One or more options correct. Select all to score.
NAT: Numerical response. No negative marking.
Scientific calculator allowed for all calculations.
Official answer key is sealed at the end of this sheet.

End Term · 31 Aug 2025 (FN)End Term

Q1MCQ3 Marks·Choose one option
Asked 4 times Key ↓
Consider the following Python code: class Employee: def __init__(self, name): self.name = name self.role = "Employee" def show_details(self): print(f"{self.name} works as {self.role}") class Developer(Employee): def __init__(self, name): super().__init__(name) self.role = "Developer" def show_details(self): print(f"{self.name} writes code as a {self.role}") super().show_details() class Manager(Employee): def __init__(self, name): super().__init__(name) self.role = "Manager" def show_details(self): print(f"{self.name} manages tasks as a {self.role}") super().show_details() employees = [ Developer("Ananya"), Manager("Rajeev"), Developer("Kiran") ] for emp in employees: emp.show_details() What will be the output of the code above?
1. AAnanya writes code as a Developer Ananya works as Developer Rajeev manages tasks as a Manager Rajeev works as Manager Kiran writes code as a Developer Kiran works as Developer
2. BAnanya writes code as a Developer Ananya works as Employee Rajeev manages tasks as a Manager Rajeev works as Employee Kiran writes code as a Developer Kiran works as Employee
3. CAnanya works as Developer Rajeev works as Manager Kiran works as Developer
4. DDeveloper Employee Manager Employee Developer Employee
Read the passage below, then answer Q2–Q4
Consider the following Python code and answer the sub-questions:
class Vehicle:
total_vehicles = 0
all_models = []
def __init__(self, model):
self.model = model
Vehicle.total_vehicles += 1
Vehicle.all_models.append(model)
def get_info(self):
return "Model: " + self.model
def get_total():
return Vehicle.total_vehicles
def count_models_starting_with(letter):
count = 0
for m in Vehicle.all_models:
if m.startswith(letter):
count += 1
return count
class ElectricVehicle(Vehicle):
ev_count = 0
def __init__(self, model, battery):
Vehicle.__init__(self, model)
self.battery = battery
ElectricVehicle.ev_count += 1
if battery < 40:
self.status = "Low"
else:
self.status = "OK"
def get_info(self):
return (
f"{Vehicle.get_info(self)}, "
f"Battery: {self.battery})%, "
f"Status: {self.status}"
)
class PetrolVehicle(Vehicle):
pv_count = 0
def __init__(self, model, fuel):
Vehicle.__init__(self, model)
self.fuel = fuel
PetrolVehicle.pv_count += 1
def get_info(self):
return f"{Vehicle.get_info(self)}, Fuel: {self.fuel} L"
fleet = [
ElectricVehicle("Tesla Model 3", 75),
ElectricVehicle("Mahindra e2o", 35),
PetrolVehicle("Hyundai i10", 20),
PetrolVehicle("Swift", 12),
ElectricVehicle("Tata Tigor EV", 80),
Vehicle("Generic Cycle")
]
low_battery_models = []
for v in fleet:
if isinstance(v, ElectricVehicle):
if v.status == "Low":
low_battery_models.append(v.model)
count = 0
for v in fleet:
if isinstance(v, Vehicle):
count += 1
print(count)
Q2NAT2 Marks·Write the number
Asked 3 times Key ↓
What will the output of the given code?
Your answer:
Q3MSQ2 Marks·Choose all correct options
Key ↓
Which of the following are correct?
1. AElectricVehicle.ev_count is 3
2. BPetrolVehicle.pv_count is 2
3. C"Mahindra e2o" is in low_battery_models
4. DVehicle.get_total() will raise an error
Q4MCQ1 Mark·Choose one option
Key ↓
What does fleet[1].get_info() return?
1. AModel: Mahindra e2o, Battery: 35%, Status: Low
2. BModel: Mahindra e2o, Fuel: 35L
3. CModel: Mahindra e2o
4. DModel: Mahindra e2o, Battery: 35%

End Term · 31 Aug 2025 (AN)End Term

Q5MCQ3 Marks·Choose one option
Asked 4 times Key ↓
Consider the following snippet of code: class Shape: def __init__(self): pass def area(self): return "Area not defined" def describe(self): return f"I am a shape. Area: {self.area()}" class Rectangle(Shape): def __init__(self, width, height): self.width = width self.height = height def area(self): return self.width * self.height class Circle(Shape): def __init__(self, radius): self.radius = radius r = Rectangle(4, 5) c = Circle(3) print(r.describe()) print(c.describe()) What will be the output?
1. AI am a shape. Area: 20 I am a shape. Area: Area not defined
2. BI am a shape. Area: Area not defined I am a shape. Area: Area not defined
3. CAttributeError: 'Rectangle' object has no attribute 'describe'
4. DNameError: describe is not defined
5. EI am a shape. Area: 20 I am a shape. Area: 28.26
Q6NAT3 Marks·Write the number
Asked 4 times Key ↓
Consider the below python code. class A: def __init__(self): self.value = 5 def add(self, num): self.value += num return self.value class B(A): def __init__(self): super().__init__() self.value *= 2 def add(self, num): return super().add(num * 2) obj = B() result = obj.add(3) print(result) What will be the output of the given code?
Your answer:

End Term · 13 Apr 2025 (FN)End Term

Q7MCQ3 Marks·Choose one option
Asked 3 times Key ↓
1. A
2. B
3. C
4. D
Read the passage below, then answer Q8–Q9
Based on the above data, answer the given subquestions.
Q8MCQ1.5 Marks·Choose one option
Key ↓
What will be the output of the given code?
1. AEmployee Name: Alice Salary: 75000
2. BEmployee Name: Alice Salary: 80000 Manager of Department: HR
3. CEmployee Name: Alice Salary: 80000
4. DManager of Department: HR
Q9NAT1.5 Marks·Write the number
Asked 3 times Key ↓
If the below main code is executed after the class definition, what will be the output?
Your answer:

End Term · 13 Apr 2025 (AN)End Term

Q10MCQ3 Marks·Choose one option
Asked 3 times Key ↓
1. A
2. B
3. C
4. D
Read the passage below, then answer Q11–Q12
Based on the below data answer the given subquestions.
Q11MSQ1.5 Marks·Choose all correct options
Key ↓
Which of the following statements about method overriding in PrimeProduct is true?
1. A
2. B
3. C
4. D
Q12MCQ1.5 Marks·Choose one option
Asked 3 times Key ↓
1. A1
2. B2
3. C3
4. DCannot be determined

End Term · 22 Dec 2024 (FN)End Term

Q13MCQ3 Marks·Choose one option
Asked 4 times Key ↓
1. A
2. B
3. C
4. D

End Term · 22 Dec 2024 (AN)End Term

Q14MCQ3 Marks·Choose one option
Asked 3 times Key ↓
1. A
2. B
3. C
4. D

Official Key

Master Answer Key & Explanations

Official answer keys from IIT Madras BS past papers. Click any question to review.

Reveal Key

Q1A

Q26

Q3A, B, C

Q4A

Q5A

Q616

Q7C

Q8B

Q93

Q10B

Q11A, B, D

Q12B

Q13C

Q14B

Questions and answer keys are reproduced from the official IIT Madras BS papers. Topics and repeated question types are BTechi’s own grouping. BTechi is not affiliated with IIT Madras.