M.C.A. (Online Mode) Semester I Examination

Paper Code: OCA-501 MJ
Title: Programming from First Principles
Time: 3 Hours
Maximum Marks: 70

Q1) Multiple Choice Questions with reasoning — answer any 25 of 30 [25 × 2 = 50]

For every attempted question, select one option and give a brief reason.

No.	Question	A	B	C	D
1	Which built-in type is immutable?	list	dict	set	tuple
2	What is len({1, 1, 2})?	1	2	3	Error
3	A higher-order function must do what?	Use a loop	Take or return a function	Be recursive	Return a list
4	filter(f, xs) retains items for which f returns what?	A number	A string	A truthy value	None
5	In if/elif/else, how many branches execute in one pass?	All true branches	At most one	Exactly two	None always
6	A list comprehension normally produces what?	A generator	A list	A class	A function
7	Why is a generator called lazy?	It sorts automatically	It produces values on demand	It cannot be iterated	It stores only strings
8	What does yield normally do?	Ends the process	Suspends state and emits a value	Deletes locals	Imports a module
9	A Python lambda may contain what?	Multiple statements	One expression	A class definition	A while statement
10	Lambda abstraction means what?	Naming a file	Defining a function of a variable	Calling a function	Deleting a binding
11	A first-class function can be what?	Passed as an argument	Used only after class	Stored only globally	Returned but not stored
12	A closure captures variables from where?	A database	Its enclosing lexical scope	The import cache	A type checker
13	A function factory usually returns what?	A configured function	A loop	A module	A syntax error
14	If f = g, what does f refer to?	The result of calling g	The function object g	The string "g"	Nothing
15	Dynamic typing associates types primarily with what?	Names forever	Runtime values	Source files	Indentation
16	Type hints are normally what?	Runtime enforcement	Metadata for tools and readers	A replacement for tests	Required everywhere
17	TypeVar('T') is useful for expressing what?	A fixed integer	A relationship among generic types	Runtime casting	File types
18	A generic identity function should use what signature idea?	Unrelated Any types	The same type variable for input and output	Only object	No return type
19	A user-defined type is commonly created with which keyword?	class	yield	break	continue
20	An Enum is best suited to what?	Arbitrary changing strings	A fixed set of named choices	Mutable sequences	Anonymous functions
21	Every terminating recursive solution needs what?	A class	A reachable base case	A global variable	A generator
22	Recursive calls are tracked using what?	The call stack	The import path	A type table	A database
23	Operational semantics describes what?	Program-state changes during execution	Naming conventions	File layout	Documentation style
24	Syntax answers which question?	What does it do?	Is it grammatically well formed?	How fast is it?	Who wrote it?
25	Duck typing focuses on an object's what?	Declared ancestry only	Supported behaviour	Memory address	File name
26	A Protocol describes what?	Required operations or structure	A concrete constructor only	A loop invariant	A network connection
27	Polymorphism allows what?	One interface to work with multiple types	Variables to have no value	Classes to store identical data	Programs to avoid functions
28	Parametric polymorphism is represented by what?	Generics or type parameters	Only inheritance	Global variables	Exceptions
29	What is list(map(lambda x: x * 2, [1, 2]))?	[1, 2]	[2, 4]	[2, 2]	A function
30	What is the conventional value of factorial(0)?	0	1	Undefined	−1

Q2) Answer any five in approximately two sentences [5 × 2 = 10]

1. Distinguish a list from a tuple.
2. What is a pure function?
3. Explain the difference between return and yield.
4. Why are type hints useful even though Python is dynamically typed?
5. What does @dataclass provide?
6. State the base case and recursive case of factorial.
7. Distinguish a protocol from a concrete class.

Q3) Answer any two in approximately ten lines [2 × 5 = 10]

1. Explain higher-order functions using map, filter, and one short Python example.
2. Compare eager list construction with lazy generator evaluation, including benefits and limitations.
3. Trace factorial(4) recursively and explain the role of the call stack.
4. Explain dynamic typing, strong typing, type hints, Any, and TypeVar in Python.