Question 1: Define the term 'array' as used in programming and give an example of what it might store.

Answer: An array is a collection of elements stored in contiguous memory locations, accessible by an index. For example, an array of integers storing test scores: [85, 90, 78, 92].

Question 2: Describe a real-world scenario where a linked list would be more suitable than an array.

Answer: A linked list is more suitable when frequent insertions and deletions are required, such as managing a playlist where songs are added or removed dynamically.

Question 3: Complete the truth table for a NAND gate with inputs A and B. The table should include all possible input combinations and output.

Answer: Inputs A and B: 0 0, 0 1, 1 0, 1 1. Outputs: 1, 1, 1, 0.

Question 4: Draw a logic circuit for an AND gate connected to two input variables, A and B. Label the circuit clearly.

Answer: A correct sketch would show two lines leading into an AND gate symbol, with the output labeled as A AND B.

Question 5: Explain the difference between a stack and a queue data structure.

Answer: A stack is a Last In First Out (LIFO) structure where the last element added is the first to be removed. A queue is a First In First Out (FIFO) structure where the first element added is the first to be removed.

Question 6: Sketch a flowchart for a program that checks if a number is positive, negative, or zero. Use standard flowchart symbols.

Answer: A flowchart starting with a start symbol, then a decision box asking 'Is number > 0?'. If yes, output 'Positive'; if no, another decision 'Is number < 0?'. If yes, output 'Negative'; else output 'Zero'. End symbol at the end.

Question 7: What is the primary purpose of a hash table in data management?

Answer: A hash table allows for fast data retrieval by mapping keys to values using a hash function.

Question 8: Draw a binary search tree containing the numbers 15, 10, 20, 8, 12, 17, 25. Show the structure clearly.

Answer: A sketch with 15 as root, 10 as left child of 15, 20 as right child of 15, 8 as left child of 10, 12 as right child of 10, 17 as left child of 20, and 25 as right child of 20.

Question 9: List three advantages of using a linked list over an array.

Answer: Dynamic size, efficient insertions and deletions, and no need to allocate memory upfront.

Question 10: Describe how an XOR gate functions with two inputs, and list all possible input combinations with their outputs.

Answer: An XOR gate outputs 1 when inputs are different and 0 when they are the same. The combinations: 0 0 -> 0, 0 1 -> 1, 1 0 -> 1, 1 1 -> 0.

Question 11: Sketch a simple decision tree for determining if a person is eligible to vote based on age (18 or older) and citizenship status (UK citizen).

Answer: