Question 1: Describe in your own words what data compression is and explain why it is useful in computing.

Answer: Data compression reduces the size of data to save storage space or decrease transmission time. It is useful because it makes data transfer faster and storage more efficient.

Question 2: Explain the difference between lossy and lossless compression, providing one example of each.

Answer: Lossless compression reduces data size without losing any information, such as ZIP files. Lossy compression reduces data size by removing some data, which may reduce quality, such as JPEG images.

Question 3: Given a binary data string: 110100101111, suggest a simple form of run-length encoding (RLE) compression for this data.

Answer: RLE would encode the data by counting consecutive identical bits. For example, '11' becomes '2x1', '0' becomes '1x0', etc. The compressed form might be: 2x1, 1x0, 1x1, 2x0, 1x1, 3x1.

Question 4: Complete the truth table for an AND gate with inputs A and B, and output C.

Answer: | A | B | C | |---|---|---| | 0 | 0 | 0 | | 0 | 1 | 0 | | 1 | 0 | 0 | | 1 | 1 | 1 |

Question 5: Complete the truth table for an OR gate with inputs A and B, and output C.

Answer: | A | B | C | |---|---|---| | 0 | 0 | 0 | | 0 | 1 | 1 | | 1 | 0 | 1 | | 1 | 1 | 1 |

Question 6: Draw a logic circuit that represents the expression: (A AND B) OR C.

Answer: A correct sketch would include: two AND gates, with inputs A and B feeding into one, and input C feeding directly into an OR gate along with the output of the AND gate.

Question 7: Sketch a diagram of a simple data compression process where uncompressed data is reduced in size.

Answer: A suitable sketch shows a block labeled 'Uncompressed Data' leading to a block labeled 'Compression Algorithm,' resulting in a smaller 'Compressed Data' block, with arrows indicating the data flow.

Question 8: Explain why data compression might sometimes result in data loss, and give an example of when this might be acceptable.

Answer: Data compression can result in data loss if lossy methods remove information to reduce size, which may be acceptable in images or videos where slight quality reduction is not noticeable.

Question 9: Describe a real-world scenario where data compression significantly improves system performance.

Answer: Streaming videos online benefits from data compression as it reduces bandwidth usage and allows smoother playback despite limited internet speeds.

Question 10: Explain how lossless compression differs from lossy compression in terms of data recovery.

Answer: Lossless compression allows the original data to be perfectly reconstructed, whereas lossy compression results in some data being permanently lost.

Question 11: Identify two types of data that are typically compressed using lossless methods and justify your choices.

Answer: Text files and software programs are typically compressed losslessly because losing any data could corrupt the file or change its function.