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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 888 · 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.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) tell it your passwords (b) put it in the bathroom (c) let strangers use it (d) mute it when not in use
  2. 2.Which of these wastes electricity? (a) unplug idle chargers (b) close the fridge quickly (c) use old filament bulbs (d) use daylight to read
  3. 3.🔺 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
  4. 4.True or false: to set a strong password is a risky habit. (a) True (b) False
  5. 5.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the length of a wire (d) the colour of light
  6. 6.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the output (c) the process (d) the battery
  7. 7.Which drawing is the symbol for a junction? (a) a dot where wires meet (b) two equal parallel lines (c) one tall, one short bar (d) triangle against a bar
  8. 8.⚡ A device works on 24 V and takes 3 A. What is its power (in watts)? =
  9. 9.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) list inputs and outputs (b) test it and fix it (c) build it with an adult (d) pick a problem to solve
  10. 10.True or false: one tall, one short bar is the symbol for an LED. (a) True (b) False
  11. 11.⏱️ loop forever { LED ON; wait 700 ms; LED OFF; wait 950 ms }
    How many milliseconds does one blink (ON + OFF) take?
  12. 12.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 17 °C. What is shown?     (a) Cool (b) Hot (c) Warm
  13. 13.Which of these is an input? (a) an LED (b) a speaker (c) a motor (d) a keypad
  14. 14.🧩 Which component boosts a small signal? (a) resistor (b) thermistor (c) transistor (d) diode
  15. 15.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
  16. 16.🧮 A 330 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  17. 17.Which of these is a good habit? (a) accept every permission (b) share camera links (c) keep factory passwords (d) set up with a parent
  18. 18.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a resistor (c) a capacitor (d) a diode
  19. 19.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
  20. 20.🔋 How many 1.2 V cells must be joined in series to give 9.6 V?
  21. 21.True or false: a circle with a cross is the symbol for a diode. (a) False (b) True
  22. 22.🌐 Is a plain table fan an IoT device? (a) not an IoT device (b) an IoT device
  23. 23.⚡ What does a night lamp mainly change electricity into? (a) heat (b) sound (c) movement (d) light
  24. 24.🔦 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
  25. 25.📏 How many amperes (A) is 750 mA? =
  26. 26.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) in parallel (d) not joined
  27. 27.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) the bulb is unscrewed (d) all wires are joined
  28. 28.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) No (b) Yes
  29. 29.💡 6 identical bulbs are in parallel and each one takes 0.5 A. What total current (in amperes) comes from the battery? =
  30. 30.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
  31. 31.True or false: a line lifted at a gap is the symbol for a voltmeter. (a) False (b) True
  32. 32.🔍 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
  33. 33.💡 In a series circuit, how many paths does the current have? (a) none (b) one for each bulb (c) two (d) one
  34. 34.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
  35. 35.🧩 Which component blows if current is high? (a) motor (b) fuse (c) LED (d) buzzer
  36. 36.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) bigger (d) smaller
  37. 37.📏 How many kilowatts (kW) is 3500 W? =
  38. 38.🔁 x = 4
    repeat 5 times { x = x × 2 }
    What is x at the end?
  39. 39.🔁 repeat 6 times { repeat 6 times { beep } }
    How many beeps are there?
  40. 40.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False

Answer key

  1. mute it when not in use
  2. use old filament bulbs
  3. R = V ÷ I
  4. False
  5. energy used each second
  6. the process
  7. a dot where wires meet
  8. 72
  9. build it with an adult
  10. False
  11. 1650
  12. Cool
  13. a keypad
  14. transistor
  15. 2
  16. 495
  17. set up with a parent
  18. a buzzer
  19. safe
  20. 8
  21. False
  22. not an IoT device
  23. light
  24. Yes
  25. 0.75
  26. in series
  27. all wires are joined
  28. Yes
  29. 3
  30. No
  31. False
  32. 6
  33. one
  34. True
  35. fuse
  36. bigger
  37. 3.5
  38. 128
  39. 36
  40. False

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