Computational Thinking and Programming-I Quiz 6

✅ Answer: (c) Errors that violate the rules of the programming language

Syntax errors happen when code breaks the grammar rules of the language — like a missing colon or an unclosed bracket. Python catches these before the program even starts running.

✅ Answer: (a) print(“Hello” (a missing closing parenthesis)

A missing closing parenthesis breaks Python’s grammar rules and is caught immediately as a genuine SyntaxError — the program won’t even start. (Note: this question is corrected from a widely circulated version whose four options were actually all runtime or logical errors, with no true syntax error among them. Dividing by zero is a runtime ZeroDivisionError, an undefined variable raises a runtime NameError, and an infinite loop is a logical error.)

✅ Answer: (c) Errors that result in incorrect program output

Logical errors don’t crash the program or trigger any error message — the code runs perfectly fine, but produces the wrong output because the underlying logic itself is flawed.

✅ Answer: (c) Using an incorrect algorithm

Using an incorrect algorithm is a classic logical error — the program runs without crashing, but the wrong approach means it produces the wrong result. Dividing by zero causes a runtime error, and misspelling a variable name causes a NameError at runtime — neither is purely “logical”.

✅ Answer: (a) Errors that occur during program execution

Run-time errors occur while the program is actually running — the syntax is valid and execution starts fine, but something goes wrong partway through (like dividing by zero), causing the program to crash.

✅ Answer: (d) Division by zero in the program

Division by zero is a textbook run-time error — the code is syntactically correct and starts executing fine, but crashes with a ZeroDivisionError the moment that specific line runs.

✅ Answer: (b) By the computer at compile/translation time

Syntax errors are caught by the computer during translation, before execution begins — Python parses the entire code first, and if the grammar is broken anywhere, it refuses to run the program at all.

✅ Answer: (d) By running the program and analyzing the output

Logical errors are the trickiest to catch because the computer sees nothing wrong — no crash, no error message. They’re only found by running the program and checking whether the output actually matches what was expected.

✅ Answer: (c) By the computer at run-time

Run-time errors are detected by the computer while the program is actively executing — the interpreter halts and raises an exception the moment it hits the problematic line.

✅ Answer: (b) Logical errors

Logical errors are the hardest to debug — the program runs without crashing and gives no error message at all, so you have to carefully trace through the logic yourself to figure out why the output is wrong.

✅ Answer: (b) try / except

try / except lets you “attempt” a block of risky code and catch any exception it raises, so the program can respond gracefully instead of crashing outright.

✅ Answer: (c) IndexError

Trying to access an out-of-range position, like L[10] on a 3-item list, raises an IndexError.

✅ Answer: (a) ZeroDivisionError

Python raises a ZeroDivisionError specifically for this case — e.g. print(5/0) immediately crashes with this exception.

✅ Answer: (d) NameError

Referring to a variable that was never assigned a value raises a NameError, with a message like “name ‘x’ is not defined”.

✅ Answer: (b) TypeError

Trying to add a string and an integer directly raises a TypeError — Python won’t silently guess how to combine incompatible types.

✅ Answer: (c) ValueError

Since “abc” isn’t a valid whole number, int("abc") raises a ValueError — the type of the argument is fine (it’s a string), but its content/value is not valid for the conversion.

✅ Answer: (c) finally

The finally block always executes — whether the try block succeeded, raised an exception, or the exception was caught — making it ideal for cleanup tasks like closing a file.

✅ Answer: (b) A report showing the sequence of function calls that led to an error

A traceback is the error report Python prints when an exception isn’t caught — it shows the chain of function calls (and line numbers) that led up to the error, which is invaluable for debugging.

✅ Answer: (b) Testing finds errors in a program; debugging fixes them

Testing is the process of running a program to discover whether errors exist (and where). Debugging is the separate, subsequent process of actually locating the root cause and fixing it.

✅ Answer: (c) Syntax error

Forgetting a required colon (:) after if, for, or def breaks Python’s required grammar, making it a syntax error — caught immediately, before the program can even begin running.