Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 362 · 40 questions

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.

1. 1.🤖 if (light < 200) { lamp ON } else { lamp OFF }
   The light sensor reads 59. What happens? (a) lamp ON (b) lamp OFF
2. 2.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
3. 3.🧮 Three equal 75 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
4. 4.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
5. 5.🔍 Which is the odd one out? (a) build with an adult near (b) use small battery cells (c) touch a switch when wet (d) stay away from pylons
6. 6.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
   The temperature is 37 °C. What is shown? (a) Hot (b) Cool (c) Warm
7. 7.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
8. 8.Which of these uses electricity? (a) a generator (b) a television (c) a bicycle dynamo (d) a wind turbine
9. 9.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
10. 10.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire has come loose (d) the switch is ON
11. 11.🔺 A current of 25 mA flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 45 °C. What is shown? (a) Warm (b) Cool (c) Hot
13. 13.True or false: “many values in a range” is a digital signal. (a) False (b) True
14. 14.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) False (b) True
15. 15.🔁 count = 0
    repeat 3 times { count = count + 10 }
    What is count at the end?
16. 16.🔌 Is a rubber eraser a conductor or an insulator? (a) a conductor (b) an insulator
17. 17.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
18. 18.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) gets smaller (d) stays the same
19. 19.🏠 Which is a smart-home example? (a) a hand fan (b) lights on from an app (c) a printed map (d) a candle in a jar
20. 20.🔌 Is an iron nail a conductor or an insulator? (a) a conductor (b) an insulator
21. 21.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
23. 23.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) a parent or guardian (c) an online stranger (d) nobody at all
24. 24.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
25. 25.⏱️ repeat 2 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
26. 26.🔺 A current of 0.5 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
27. 27.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
28. 28.Which of these wastes electricity? (a) set the AC to 24 °C (b) leave fridge door open (c) close the fridge quickly (d) use LED lamps
29. 29.🤖 Microcontroller or laptop: which one runs many apps at once? (a) microcontroller (b) laptop
30. 30.🤖 Does a digital thermometer usually have a microcontroller inside? (a) Yes (b) No
31. 31.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
32. 32.📏 How many ohms (Ω) is 7.9 kΩ?
33. 33.True or false: an electric toy car mainly makes sound. (a) False (b) True
34. 34.What does a transistor do? (a) is a resistance knob (b) boosts a small signal (c) makes a beeping sound (d) has coloured bands
35. 35.Which of these is an insulator? (a) a safety pin (b) a paper strip (c) a brass key (d) a metal paper clip
36. 36.🔍 Which is the odd one out? (a) change default passwords (b) cover unused cameras (c) turn off unused gadgets (d) share camera links
37. 37.🌈 A resistor has the colour bands orange, orange, orange. What is its value in kilo-ohms (kΩ)? =
38. 38.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
39. 39.🧩 Which component makes a beeping sound? (a) diode (b) LED (c) buzzer (d) fuse
40. 40.Which of these is a risky habit? (a) change default passwords (b) ignore update messages (c) cover unused cameras (d) turn off unused gadgets

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