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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 961 · 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.

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  1. 1.⏱️ How many milliseconds is a wait of 0.6 seconds?
  2. 2.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) True (b) False
  3. 3.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) blinks an LED (d) joins two wires
  4. 4.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  5. 5.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end?     (a) ON (b) OFF
  6. 6.True or false: an iron nail is a conductor. (a) True (b) False
  7. 7.🔺 A current of 25 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  8. 8.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
  9. 9.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = I × R (d) V = R ÷ I
  10. 10.⚠️ Is it safe to touch a switch when wet? (a) safe (b) not safe
  11. 11.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) all wires are joined (d) the switch is ON
  12. 12.🔋 Does a solar panel give electricity or use electricity? (a) uses electricity (b) gives electricity
  13. 13.🌈 In the resistor colour code, which number does green stand for?
  14. 14.🌐 Is a plain table fan an IoT device? (a) not an IoT device (b) an IoT device
  15. 15.Which of these gives us electricity? (a) a mobile phone (b) a television (c) an air conditioner (d) a bicycle dynamo
  16. 16.🔺 A current of 20 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
  17. 17.Which job needs a buzzer? (a) beep an alarm (b) show the temperature (c) open a gate to 90° (d) show a status light
  18. 18.Which drawing is the symbol for a capacitor? (a) many long-short pairs (b) a circle with a cross (c) two equal parallel lines (d) a circle with an X in it
  19. 19.Which of these is an output? (a) a motion sensor (b) a sound sensor (c) a servo motor (d) a keypad
  20. 20.🔍 Which is the odd one out? (a) a motion sensor (b) a sound sensor (c) a motor (d) a light sensor
  21. 21.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) sound energy (b) chemical energy (c) movement energy (d) light energy
  22. 22.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V + I (d) R = V ÷ I
  23. 23.💡 4 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
  24. 24.🌐 Is a paper calendar an IoT device? (a) not an IoT device (b) an IoT device
  25. 25.⚡ An 18 W device works on 12 V. What current does it take (in amperes)? =
  26. 26.⚡ What does a tube light mainly change electricity into? (a) light (b) sound (c) heat (d) movement
  27. 27.True or false: to keep drinks far away is not safe. (a) True (b) False
  28. 28.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
  29. 29.Which of these has no microcontroller inside? (a) a smart watch (b) a wind-up toy (c) a digital thermometer (d) a TV remote
  30. 30.Which job needs a distance sensor? (a) water a dry plant (b) switch on lamps at dusk (c) stop a robot near walls (d) open blinds at sunrise
  31. 31.⚙️ Which actuator would you use to show the temperature? (a) a buzzer (b) a display (c) a motor (d) a servo motor
  32. 32.🔺 A current of 1.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  33. 33.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a buzzer (c) a capacitor (d) a diode
  34. 34.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  35. 35.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 550 ms }
    How many milliseconds does one blink (ON + OFF) take?
  36. 36.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 100 (b) 1024 (c) 1000 (d) 10
  37. 37.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
  38. 38.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
  39. 39.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
  40. 40.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) not joined (d) in series

Answer key

  1. 600
  2. False
  3. stores a value
  4. wastes electricity
  5. OFF
  6. True
  7. 400
  8. 460
  9. V = I × R
  10. not safe
  11. the bulb is unscrewed
  12. gives electricity
  13. 5
  14. not an IoT device
  15. a bicycle dynamo
  16. 4
  17. beep an alarm
  18. two equal parallel lines
  19. a servo motor
  20. a motor
  21. movement energy
  22. R = V ÷ I
  23. 2
  24. not an IoT device
  25. 1.5
  26. light
  27. False
  28. + (positive)
  29. a wind-up toy
  30. stop a robot near walls
  31. a display
  32. 9
  33. a buzzer
  34. 10
  35. 800
  36. 1000
  37. Yes
  38. True
  39. input
  40. in series

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