Time allowed: 40 minutes
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INSTRUCTIONS
- Use black ink.
- Answer all the questions.
INFORMATION
- The total mark for this paper is 29.
- The marks for each question are shown in brackets [ ].
Turn over
Section A: Low-Frequency "Ghost Topics"
1
A common misconception is that casting a Real number to an Integer rounds it to the nearest whole number.
(a) State the value of the variable
x after the following line of code is run:
x = int(9.9)
[1]
(b) Explain how the computer arrived at this value (refer to the specific behavior of the
int() function).
[1]
2
The OCR specification requires knowledge of
ASC() and
CHR().
ASC(character) casts a character to its ASCII integer value.CHR(integer) casts an integer to its ASCII character value.
Given that the ASCII value for 'A' is 65, complete the trace table for the following algorithm.
char1 = 'A'
val1 = ASC(char1)
val2 = val1 + 2
char2 = CHR(val2)
print(char2)
[4]
| char1 |
val1 |
val2 |
char2 |
Output |
| 'A' |
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3
Determine the final value of the variable
result in each case.
[3]
| Code |
Final Value |
Data Type |
result = str(10 + 5) |
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result = int("12") + 5 |
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result = float(int(4.8)) |
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4
A student wants to convert the user's input (the text "True" or "False") into a real Boolean value.
They write this code:
userInput = input("Enter True or False: ")
isValid = bool(userInput)
(a) Explain why this code logic fails if the user types "False".
(Hint: In Python,
bool("non-empty string") evaluates to True).
[2]
(b) Rewrite the code using an
IF statement to correctly set the variable
isValid to the Boolean
False if the input is "False".
[2]
Turn over
5
Write a short algorithm that generates a random capital letter (A–Z).
- You must generate a random Integer between 65 and 90.
- You must Cast this integer to a Character before printing it.
Note: random(min, max) generates a random number.
[3]
Section B: High-Frequency Baseline Skills
6
The following code attempts to calculate a user's age in months and print it.
It contains a
Type Mismatch Error.
01 ageYears = int(input("Enter age in years: "))
02 ageMonths = ageYears * 12
03 print("You are " + ageMonths + " months old.")
(a) Identify the line number where the error occurs.
[1]
Line:
(b) Rewrite the line to fix the error using casting.
[2]
7
A program needs to calculate the area of a circle. The radius may be a decimal number (e.g., 5.5).
Fill in the missing keywords to ensure the calculation works.
[3]
radiusString = input("Enter radius: ")
radiusVal = ..............................(radiusString) # Must handle decimals
area = 3.142 * (radiusVal * radiusVal)
print("The area is " + ..............................(area))
8
State the output of the following code.
x = "10"
y = "2"
print(x + y)
[2]
9
Explain why casting a Real value to an Integer is considered a "narrowing" conversion, and what risk this poses to the accuracy of data.
[2]
END OF QUESTION PAPER