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Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 133 · 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.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second
  2. 2.🔋 5 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
  3. 3.🔺 A 3.3 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
  4. 4.🌐 Is a battery torch an IoT device? (a) an IoT device (b) not an IoT device
  5. 5.🧩 Which component limits the current? (a) resistor (b) capacitor (c) transistor (d) fuse
  6. 6.Which of these is an IoT device? (a) a battery torch (b) a wind-up clock (c) a plain wall switch (d) a Wi-Fi doorbell camera
  7. 7.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they fix security holes (c) they delete the Wi-Fi (d) they change the colour
  8. 8.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the if part (c) the else part (d) both parts
  9. 9.⚡ A device works on 6 V and takes 2 A. What is its power (in watts)? =
  10. 10.Which of these is a good habit? (a) share the Wi-Fi key (b) tap unknown app links (c) post your live location (d) install software updates
  11. 11.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the process (c) the battery (d) the output
  12. 12.True or false: to touch a fallen wire is not safe. (a) False (b) True
  13. 13.🧩 Which component turns a fan or wheels? (a) diode (b) LED (c) motor (d) transistor
  14. 14.🌈 A resistor has the colour bands violet, green, yellow. What is its value in kilo-ohms (kΩ)? =
  15. 15.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 15 °C. What is shown?     (a) Cool (b) Warm (c) Hot
  16. 16.Which job needs a temperature sensor? (a) keep an incubator warm (b) warn of a gas leak (c) switch on lamps at dusk (d) switch on with a clap
  17. 17.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
  18. 18.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) the same voltage (c) half the voltage (d) double the voltage
  19. 19.True or false: to iron one shirt at a time saves electricity. (a) False (b) True
  20. 20.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is ON. Does the bulb glow? (a) No (b) Yes
  21. 21.True or false: a metal paper clip is an insulator. (a) False (b) True
  22. 22.Which drawing is the symbol for an ammeter? (a) a plain rectangle (b) a circle with V inside (c) a circle with A inside (d) triangle against a bar
  23. 23.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No
  24. 24.🧮 Resistors of 330 Ω, 22 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
  25. 25.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) it starts again (c) the board breaks (d) it deletes itself
  26. 26.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 900 ms }
    How many milliseconds does one blink (ON + OFF) take?
  27. 27.True or false: the ammeter is joined across a part. (a) False (b) True
  28. 28.📏 Which unit measures energy used each second? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
  29. 29.🔍 Which is the odd one out? (a) fly a kite near wires (b) use mains for a project (c) fly kites in open fields (d) open a phone charger
  30. 30.💡 A red LED uses 2 V and should get 20 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
  31. 31.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 38 %. What happens?     (a) pump ON (b) pump OFF
  32. 32.🔍 Which is the odd one out? (a) a speaker (b) a servo motor (c) an LED (d) a temperature sensor
  33. 33.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
  34. 34.⏱️ A program says “wait 7750 ms”. How many seconds is that? =
  35. 35.💡 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 HIGH
    Is the LED ON or OFF at the end?     (a) ON (b) OFF
  36. 36.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) True (b) False
  37. 37.True or false: “a single current path” is true of a series circuit. (a) True (b) False
  38. 38.🔺 An 18 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  39. 39.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
  40. 40.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) False (b) True

Answer key

  1. energy used each second
  2. 1.2
  3. 10
  4. not an IoT device
  5. resistor
  6. a Wi-Fi doorbell camera
  7. they fix security holes
  8. the else part
  9. 12
  10. install software updates
  11. the process
  12. True
  13. motor
  14. 750
  15. Cool
  16. keep an incubator warm
  17. parallel
  18. the same voltage
  19. False
  20. No
  21. False
  22. a circle with A inside
  23. No
  24. 822
  25. it starts again
  26. 1100
  27. False
  28. watt (W)
  29. fly kites in open fields
  30. 350
  31. pump ON
  32. a temperature sensor
  33. open
  34. 7.75
  35. ON
  36. True
  37. True
  38. 3
  39. series
  40. False

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