02.01 Control Structures - Quiz

Check your understanding

1. What is the main characteristic of sequence control structure?

   • Steps are executed one after another in a fixed order { data-correct }
   • Steps are repeated multiple times based on a condition
   • Steps are executed only if certain conditions are met
   • Steps can be executed in any order

2. Look at this flowchart. What type of control structure does it represent?

   flowchart TD
       A[Start] --> B{Temperature > 30°C?}
       B -->|Yes| C[Turn on air conditioning]
       B -->|No| D[Open windows]
       C --> E[End]
       D --> E
   

   • Sequence
   • Selection (IF-THEN-ELSE) { data-correct }
   • Iteration (loop)
   • Multiple selection (CASE)

3. Which type of loop should you use when you know exactly how many times to repeat an action?

   • FOR loop (counted loop) { data-correct }
   • WHILE loop (conditional loop)
   • IF-THEN loop
   • CASE loop

4. Trace through this algorithm with input numbers 8, 3, 12. What will be the final value of ‘result’?

   ALGORITHM Mystery
   BEGIN
       INPUT a, b, c
       SET result = a
   
       IF b > result THEN
           SET result = b
       END IF
   
       IF c > result THEN
           SET result = c
       END IF
   
       OUTPUT result
   END
   

   • 8
   • 3
   • 12 { data-correct }
   • 23

5. What will this loop output?

   SET counter = 1
   WHILE counter <= 3 DO
       OUTPUT counter * 2
       SET counter = counter + 1
   END WHILE
   

   • 1, 2, 3
   • 2, 4, 6 { data-correct }
   • 2, 4, 6, 8
   • 1, 4, 9

6. Which control structure is shown in this flowchart?

   flowchart TD
       A[Start] --> B[Set count = 1]
       B --> C{count <= 5?}
       C -->|Yes| D[Print count]
       D --> E[count = count + 1]
       E --> C
       C -->|No| F[End]
   

   • Sequence
   • Selection (IF-THEN-ELSE)
   • Iteration (WHILE loop) { data-correct }
   • Multiple selection (CASE)

7. You want to create an algorithm that processes student grades until the user enters -1 to stop. Which control structure combination would be most appropriate?

   • Only sequence - just process grades in order
   • Only selection - check if grade is valid
   • Selection inside iteration - loop until -1, checking validity each time { data-correct }
   • Only iteration - just repeat the same process

8. What is the purpose of tracing an algorithm?

   • To make the algorithm run faster
   • To convert it to a programming language
   • To verify it works correctly by following through step-by-step with sample data { data-correct }
   • To create flowcharts from pseudocode