Practice A1.2 Data representation and computer logic with authentic IB Computer Science (First Exam 2027) exam questions for both SL and HL students. This question bank mirrors Paper 1, 2, 3 structure, covering key topics like programming concepts, algorithms, and data structures. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
A digital audio system processes sound data at different bit depths and sampling rates.
Calculate the file sizes and complete the table for one minute of audio:
| Bit Depth | Sampling Rate | Channels | File Size (MB) | Quality Level |
|---|---|---|---|---|
| 16-bit | 44.1 kHz | 2 | CD Quality | |
| 24-bit | 96 kHz | 2 | ||
| 32-bit | 192 kHz | 6 | Studio Master |
Analyze how quantization affects audio quality and explain why higher bit depths reduce quantization noise.
A digital security system uses various logic circuits for access control.
Design and complete the truth table for a security system that grants access when: Card Reader AND (Fingerprint OR PIN) is satisfied:
| Card Reader | Fingerprint | PIN | Fingerprint OR PIN | Access Granted |
|---|---|---|---|---|
| 0 | 0 | 0 | ||
| 0 | 0 | 1 | ||
| 0 | 1 | 0 | ||
| 0 | 1 | 1 | ||
| 1 | 0 | 0 | ||
| 1 | 0 | 1 | ||
| 1 | 1 | 0 | ||
| 1 | 1 | 1 |
Construct Boolean expression and explain gate implementation.
A security system uses various data encoding methods.
Explain the difference between lossy and lossless data compression.
State one example each of lossy and lossless compression formats.
Outline why ASCII encoding is limited for international applications.
A data compression algorithm analyzes file types for optimal compression strategies.
Complete the compression analysis table for different file types:
| File Type | Original Size | Compressed Size | Compression Ratio | Compression Type | Quality Loss |
|---|---|---|---|---|---|
| Text (.txt) | 1 MB | 4:1 | |||
| Image (.jpg) | 5 MB | 500 KB | Lossy | ||
| Audio (.mp3) | 40 MB | 10:1 | Some | ||
| Video (.mp4) | 1000 MB | 100 MB | |||
| Archive (.zip) | 100 MB | 2:1 | Lossless |
Analyze why different compression algorithms are more suitable for specific data types and discuss the trade-offs between compression ratio and quality.
A telecommunications company needs to implement error detection in their data transmission system.
Complete the following parity bit calculation table for even parity:
| Data Bits | Binary Representation | Parity Bit (Even) | Complete 8-bit Code |
|---|---|---|---|
| 65 (A) | 01000001 | 1 | 101000001 |
| 90 (Z) | 01011010 | 0 | 001011010 |
| 48 (0) | 00110000 | 0 | 000110000 |
| 127 | 01111111 | 1 | 101111111 |
Explain how parity bits enable error detection and discuss their limitations for error correction.
A computer graphics application processes color data in different formats.
Convert between different color representation systems and complete the table:
| RGB Values | Hexadecimal | Decimal Equivalent | Color Description |
|---|---|---|---|
| (255, 0, 0) | 16711680 | ||
| (0, 255, 255) | #00FFFF | ||
| (128, 128, 128) | Medium Gray | ||
| #800080 | 8388736 |
Explain why hexadecimal notation is preferred over decimal for representing color values in web development and graphics programming.
Data must be represented in binary format for computer processing.
Convert the decimal number 156 to binary.
Convert the hexadecimal number 2F to decimal.
Explain why hexadecimal notation is commonly used in computing.
A computer uses 8-bit two's complement representation. Calculate the decimal equivalent of the binary number 11010110.
State the range of values that can be represented using 8-bit two's complement.
Digital image processing requires understanding of data representation.
Calculate the file size of an uncompressed 1920x1080 pixel image using 24-bit color depth. Express your answer in MB.
Explain how dithering is used when converting images to lower bit depths.
Compare raster and vector image representations in terms of scalability and file size.