← Final electronics test lesson New set →

Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 183 · 40 questions
TalentJR

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

NameDateTime takenScore ___ / 40
  1. 1.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 3 seconds?
  2. 2.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
  3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the glass (d) the switch
  4. 4.Which job needs a soil moisture sensor? (a) measure classroom noise (b) keep an incubator warm (c) water a dry plant (d) open blinds at sunrise
  5. 5.⚡ What does an exhaust fan mainly change electricity into? (a) sound (b) light (c) movement (d) heat
  6. 6.True or false: a laptop needs much more power. (a) True (b) False
  7. 7.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
  8. 8.Which of these is the output? (a) a button press (b) a temperature reading (c) the fan starts (d) a motion sensor signal
  9. 9.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end?     (a) ON (b) OFF
  10. 10.🔘 Which kind of switch stays where you flip it? (a) a tilt switch (b) a reed switch (c) a push button (d) a toggle switch
  11. 11.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) True (b) False
  12. 12.Which job needs a motor? (a) open a gate to 90° (b) beep an alarm (c) spin a robot’s wheels (d) turn to an exact angle
  13. 13.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
  14. 14.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
  15. 15.🔍 Which is the odd one out? (a) change default passwords (b) install software updates (c) ignore update messages (d) cover unused cameras
  16. 16.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) wire (b) voltmeter (c) ammeter (d) junction
  17. 17.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) only when both are ON (c) never (d) when either is ON
  18. 18.🔺 A current of 1.5 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
  20. 20.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
  21. 21.⚙️ What is an actuator? (a) a sensor (b) an output that acts (c) a battery (d) a program
  22. 22.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe
  23. 23.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 1 second?
  24. 24.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
  25. 25.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
  26. 26.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
  27. 27.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
  28. 28.🔁 count = 4
    while (count < 16) { count = count + 2 }
    How many times does the loop run?
  29. 29.🔌 Most metals are good … (a) magnets only (b) conductors (c) insulators (d) batteries
  30. 30.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) stores a value (d) joins two wires
  31. 31.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
  32. 32.🔺 A current of 0.1 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
  33. 33.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the water tank lid (c) the water pressure (d) the pipe colour
  34. 34.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the colour of light (d) the length of a wire
  35. 35.True or false: a doorbell mainly gives out light. (a) False (b) True
  36. 36.📶 Digital or analog: a button: pressed or not? (a) digital (b) analog
  37. 37.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a wooden stick across the gap. Does the bulb glow? (a) No (b) Yes
  38. 38.Which of these is an input? (a) a motor (b) a speaker (c) a small display (d) a light sensor
  39. 39.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  40. 40.🔁 What does “count = count + 1” do? (a) prints 1 (b) takes 1 away (c) sets count to 1 (d) adds 1 to count

Answer key

  1. 15
  2. 15
  3. the filament
  4. water a dry plant
  5. movement
  6. True
  7. dimmer
  8. the fan starts
  9. ON
  10. a toggle switch
  11. False
  12. spin a robot’s wheels
  13. 5
  14. an LED lamp
  15. ignore update messages
  16. ammeter
  17. when either is ON
  18. 10
  19. Yes
  20. both A and B are true
  21. an output that acts
  22. not safe
  23. 5
  24. + (positive)
  25. True
  26. gets smaller
  27. 1.5
  28. 6
  29. conductors
  30. stores a value
  31. parallel
  32. 15
  33. the water pressure
  34. energy used each second
  35. False
  36. digital
  37. No
  38. a light sensor
  39. anode (+)
  40. adds 1 to count

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids