GCSE Computer Science quiz: 24 questions

Code is shown in a Python-style notation. Exam boards use their own pseudocode or reference language, so treat these as practice in tracing, not as a copy of any paper.

Set 1: number systems, tracing and the CPU

Question 1. Convert the binary number 10110110 to denary. A. 166 B. 182 C. 178 D. 186

Question 2. Convert the denary number 75 to 8-bit binary. A. 01001101 B. 01011001 C. 01001011 D. 01101011

Question 3. What is the hexadecimal number 3F in denary? A. 45 B. 63 C. 315 D. 51

Question 4. Convert the denary number 200 to hexadecimal. A. 8C B. B8 C. CA D. C8

Question 5. An 8-bit register holds 01101101. A logical shift left by two places is carried out. What does it hold now? A. 10110100 B. 00011011 C. 110110100 D. 01101100

Question 6. Add the binary numbers 00110101 and 00011110. What is the result? A. 01010001 B. 01100011 C. 01001011 D. 01010011

Question 7. A square image is 8 pixels wide and 8 pixels high and uses 4 colours. Ignoring metadata, how large is it? A. 8 bytes B. 16 bytes C. 32 bytes D. 64 bytes

Question 8. A bubble sort makes one full pass through the list [5, 2, 9, 1], swapping neighbours that are out of order. What is the list after that first pass? A. 2 5 9 1 B. 1 2 5 9 C. 2 5 1 9 D. 2 1 5 9

Question 9. What does this code print?

x = 3
y = 4
x = x + y
y = x - y
print(x, y)

A. 7 4 B. 3 4 C. 7 7 D. 7 3

Question 10. What does this code print?

total = 0
for i in range(1, 5):
    total = total + i
print(total)

A. 15 B. 6 C. 10 D. 4

Question 11. Which register holds the address of the next instruction to be fetched? A. Memory address register B. Program counter C. Accumulator D. Memory data register

Question 12. Which type of memory loses its contents when the power is turned off? A. RAM B. ROM C. Flash storage in a USB stick D. A hard disk drive

Set 2: conversions, trace tables, networks and security

Question 1. Convert the hexadecimal number A7 to 8-bit binary. A. 10100111 B. 01111010 C. 10101110 D. 10100101

Question 2. Convert the binary number 11001001 to hexadecimal. A. 9C B. C9 C. B9 D. D1

Question 3. Convert the denary number 90 to 8-bit binary. A. 01011001 B. 01101010 C. 01010110 D. 01011010

Question 4. What is the largest denary number that can be stored in 6 bits? A. 64 B. 32 C. 63 D. 31

Question 5. What does this code print?

n = 27
count = 0
while n >= 5:
    n = n - 5
    count = count + 1
print(count, n)

A. 6 2 B. 5 7 C. 4 7 D. 5 2

Question 6. In Python-style slicing, the end position is not included and counting starts at 0. What does this code print?

word = "NETWORK"
print(word[1:4])

A. NET B. ETWO C. TWO D. ETW

Question 7. What does this code print?

def f(a, b):
    if a > b:
        return a - b
    else:
        return b - a

print(f(3, 10) + f(10, 3))

A. 0 B. 7 C. 14 D. −14

Question 8. A binary search looks for 23 in the sorted list [2, 5, 8, 12, 16, 23, 38]. Checking starts with the middle item. Which value is checked second? A. 16 B. 8 C. 38 D. 23

Question 9. Which protocol is mainly used to send email from a client to a mail server? A. IMAP B. SMTP C. HTTP D. FTP

Question 10. An email pretending to be from a bank asks you to click a link and enter your login details. What is this attack called? A. Phishing B. Brute force C. Denial of service D. SQL injection

Question 11. Which UK law makes unauthorised access to computer material a crime? A. Equality Act 2010 B. Computer Misuse Act 1990 C. Copyright Act 1911 D. Freedom of Information Act 2000

Question 12. Which of these is a lossless compression method? A. Run-length encoding B. Reducing the sample rate of a sound file C. Removing fine colour detail from a photo D. Lowering the resolution of an image

Part of the GCSE Computer Science revision set: the revision guide and glossary of key terms.

GCSE Computer Science quiz

Set 1: number systems, tracing and the CPU

Set 2: conversions, trace tables, networks and security

Sources

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