Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 412 · 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.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) never (c) when both are OFF (d) when either is ON
2. 2.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.⚠️ Why must we never touch switches with wet hands? (a) water carries current (b) water makes it cold (c) it spoils the paint (d) it is just untidy
4. 4.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
5. 5.True or false: aluminium foil is a conductor. (a) True (b) False
6. 6.🔘 A bulb and a cell are joined through 4 switches on 4 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
7. 7.⚡ What do we call a flow of electric charge through a wire? (a) electric current (b) sound (c) friction (d) a magnet
8. 8.Which of these is true of a series circuit? (a) a break stops every bulb (b) many paths for current (c) one out, the rest glow (d) each gets the full volts
9. 9.True or false: resistance is measured in ohms (Ω). (a) False (b) True
10. 10.⚠️ Is it safe to throw cells in a fire? (a) not safe (b) safe
11. 11.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) waits 500 seconds (d) pauses for half a second
12. 12.⚡ A 6 W device works on 3 V. What current does it take (in amperes)? =
13. 13.Which of these is an input? (a) a motor (b) a light sensor (c) a speaker (d) a buzzer
14. 14.🔺 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
15. 15.🔺 A current of 0.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
16. 16.⏱️ repeat 5 times { buzzer ON; wait 800 ms; buzzer OFF; wait 400 ms }
    How many milliseconds does this take in all?
17. 17.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) capacitor (b) voltmeter (c) motor (d) switch
18. 18.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
19. 19.🤖 Does a wind-up toy usually have a microcontroller inside? (a) No (b) Yes
20. 20.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1
21. 21.🔍 Which is the odd one out? (a) a temperature reading (b) a light level reading (c) a soil moisture reading (d) check if temp > 30
22. 22.🔌 Is a wooden stick a conductor or an insulator? (a) an insulator (b) a conductor
23. 23.💡 4 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
24. 24.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
25. 25.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 11 °C. What is shown? (a) Warm (b) Cool (c) Hot
26. 26.⏱️ A program says “wait 5000 ms”. How many seconds is that? =
27. 27.🔍 Which is the odd one out? (a) build with an adult near (b) climb an electric pole (c) dry your hands first (d) fly kites in open fields
28. 28.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 230 V (c) 1.5 V (d) 15 V
29. 29.🔍 Which sensor would you use to start a fan when hot? (a) a distance sensor (b) a gas sensor (c) a motion sensor (d) a temperature sensor
30. 30.True or false: to use mains for a project is safe. (a) True (b) False
31. 31.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.⚡ A device works on 5 V and takes 0.25 A. What is its power (in watts)? =
33. 33.What does a motor do? (a) makes things spin (b) has coloured bands (c) smooths a wobbly supply (d) makes a beeping sound
34. 34.🌐 Is a wind-up clock an IoT device? (a) not an IoT device (b) an IoT device
35. 35.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
36. 36.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a wall socket (c) an inverter socket (d) a mains extension board
37. 37.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) diode (b) LED (c) wire (d) cell
38. 38.Which of these has no microcontroller inside? (a) a TV remote (b) a smart watch (c) a digital alarm clock (d) a wind-up toy
39. 39.Which of these uses electricity? (a) a generator (b) a cell (c) a water pump (d) a battery
40. 40.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series

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