T4.4.2 Programmable microcontrollers Quiz: KS3 Design & Technology, Unit 4

The 20 questions

1. What is a microcontroller?

   • A battery that supplies energy to a product continuously for a long period
   • A small computer on a single chip that runs a program to control inputs and outputs
   • A large computer that stores files for many users connected over a network
   • A motor that turns a shaft in response to a switch being pressed by the user

2. What does a microcontroller's program do?

   • Stores the user's music files so that they can be played through a speaker later
   • Measures how much electricity the product uses each day for the user's records
   • Tells the microcontroller how to respond to inputs and which outputs to switch
   • Keeps the battery charged by controlling the mains supply to the product continuously

3. Which programming structure repeats a set of steps while a condition is true?

   • A loop, such as a while loop or a repeat block
   • A function, which can only be used to print text to the screen of the computer
   • A comment, which is ignored by the computer when the program is run
   • A variable, which stores a value that can be changed while the program runs

4. Which structure chooses between two actions depending on a condition?

   • A variable, which stores a single value in the computer's memory until it is changed
   • A sequence, which runs each line once in order from top to bottom of the code
   • A loop, which repeats the same action a fixed number of times in a row
   • A selection, such as an if then else statement

5. What is a variable in a program?

   • A fixed value that never changes, such as the number of days in a week
   • A list of all the inputs that are connected to the microcontroller board pins
   • A command that turns an output device on or off directly without any test
   • A named location that stores a value which can change while the program runs

6. What does a delay command do in a program?

   • Deletes the variables stored in memory so that the program starts again from zero
   • Sends the program to a remote server so that the code can be shared with others
   • Increases the voltage on the output pin for a set period of time each cycle
   • Pauses the program for a set time before the next instruction runs

7. Why is a microcontroller used in many products instead of a fixed circuit?

   • It always uses less electricity than any other device of any size or type
   • It removes the need for sensors, because it decides everything without any inputs
   • Its behaviour can be changed by altering the program without rewiring the circuit
   • It can only control one output at a time, which is safer for the user

8. A microcontroller board has digital and analogue pins. What is the difference?

   • Digital and analogue pins are identical except for their colour on the board
   • Digital pins are on or off, while analogue pins read a range of voltage values
   • Analogue pins are on or off, while digital pins read a range of voltage values
   • Digital pins only send sound, while analogue pins only send light to the outputs

9. A program should light an LED when a switch is pressed. Which order of steps is correct?

   • Read the switch input, check whether it is pressed, then turn the LED output on
   • Check the LED output, then turn the switch input on, then read its value
   • Store the LED value in memory, then turn the switch input off, then read it
   • Turn the LED output on, then read the switch input, then check whether it is pressed

10. A program says: if the temperature is above 30, switch on the fan. What type of structure is this?

    • A selection structure, because the fan only switches on when the condition is met
    • A variable structure, because the temperature value is stored in memory for later use
    • A delay structure, because the fan waits for thirty seconds before it switches on
    • A loop structure, because the fan switches on again and again for a fixed count

11. Why is it useful to test a program on a microcontroller in small steps?

    • It makes the program run more slowly so that the sensors have time to warm up
    • It helps locate faults by checking each part of the program before the next part is added
    • It removes the need to check the wiring, because each step corrects any wiring errors
    • It means the program can run without any power supply connected to the board

12. What does debugging mean?

    • Finding and fixing errors in a program or circuit
    • Copying the program onto a second microcontroller without making any changes to it
    • Saving the program in a file so that it can be sent to another user by email
    • Removing all the sensors and actuators from a product in order to reduce its cost

13. A counter variable starts at 0 and increases by 1 each time a loop runs. What is its value after 5 loops?

    • 4
    • 0
    • 6
    • 5

14. A microcontroller checks a sensor 10 times each second. How long is there between each check?

    • 1 second
    • 0.1 seconds
    • 10 seconds
    • 0.01 seconds

15. What is the purpose of a comment in a program?

    • To explain the code to the reader, and it is ignored when the program runs
    • To store the value of a sensor reading in a named variable for later use
    • To send the program's result to a remote computer for storage
    • To run the code again each time a sensor reading changes in value

16. Why do programs often store sensor thresholds in variables?

    • So the microcontroller will ignore the threshold whenever its value is too high
    • So the threshold can be changed in one place without editing every line that uses it
    • So the threshold can only be set once and can never be changed afterwards
    • So the threshold is stored permanently in the sensor's own internal memory

17. In an input, processing and output cycle, what does processing involve?

    • Switching the output devices on or off using the output pins of the board
    • Making decisions and calculations using the values read from the inputs
    • Reading the values from the sensors connected to the input pins of the board
    • Supplying power to the microcontroller board from a battery pack connected to it

18. A product must respond to a button press within a fraction of a second. Which program design is best?

    • A program that waits for a key on a keyboard connected to a separate computer
    • A long delay of thirty seconds before the program reads any of its inputs at all
    • A program that runs only once when the product is first switched on by the user
    • A short loop that checks the inputs continuously and acts on them straight away

19. Why do beginners often program microcontrollers with a visual block language?

    • Blocks are the only way to program a microcontroller, and text code is not supported at all
    • Blocks remove the need to connect any sensors or outputs to the board for testing
    • Blocks make the microcontroller run faster than text code can run on the same board
    • The blocks let beginners build programs by joining commands without typing exact syntax

20. A sensor gives a value of 500, but the program needs a value from 0 to 100. What is the best approach?

    • Connect a buzzer to the input pin so that the range is shown to the user as sound
    • Replace the sensor with a larger one so that its values fall within the required range
    • Use a calculation to map the sensor value into the required range within the program
    • Store the value 500 and ignore the range, because the computer will fix it later

Related quizzes

• Properties of materials Quiz · T4.1.1 · 20 questions
• Performance of structural elements Quiz · T4.1.2 · 20 questions
• Changing movement in mechanical systems Quiz · T4.2.1 · 20 questions
• Force in mechanical systems Quiz · T4.2.2 · 20 questions
• Powering advanced electrical systems Quiz · T4.3.1 · 20 questions
• Circuits with heat, light, sound and movement Quiz · T4.3.2 · 20 questions
• Sensors and actuators Quiz · T4.4.1 · 20 questions
• Researching user needs Quiz · T1.1.1 · 20 questions
• Precise use of specialist tools Quiz · T2.1.1 · 20 questions
• Analysing the work of professionals Quiz · T3.1.1 · 20 questions