Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 246 · 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.True or false: “a soil moisture reading” is the input. (a) False (b) True
2. 2.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 10 minutes?
3. 3.🧮 Resistors of 220 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
4. 4.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) iron one shirt at a time (d) set the AC to 24 °C
5. 5.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
6. 6.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is OFF. Does the bulb glow? (a) Yes (b) No
7. 7.What does a resistor do? (a) stores a little charge (b) blows if current is high (c) senses how hot it is (d) limits the current
8. 8.🔺 A current of 0.5 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
10. 10.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) compare with the limit (b) read the soil sensor (c) switch the pump on/off (d) wait a few seconds
11. 11.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
12. 12.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they get dimmer (c) they explode (d) they all go out
13. 13.🧭 Which part of a microcontroller board shows the board is on? (a) the pins (b) the power LED (c) the USB port (d) the reset button
14. 14.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
15. 15.🧮 A 1.6 V battery is joined to 8 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
16. 16.🔺 A current of 50 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
17. 17.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 32 %. What happens? (a) pump ON (b) pump OFF
18. 18.True or false: a glass marble is an insulator. (a) False (b) True
19. 19.🤖 Microcontroller or laptop: which one needs much more power? (a) microcontroller (b) laptop
20. 20.🔘 When a switch is ON, the circuit is … (a) cut (b) open (c) broken (d) closed
21. 21.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) measures light (d) blinks an LED
22. 22.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) Yes (b) No
23. 23.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True
24. 24.🤖 How does a new program get onto a microcontroller board? (a) sent by sound (b) typed on the chip (c) drawn with a pen (d) uploaded over USB
25. 25.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
26. 26.⚙️ Which actuator would you use to open a gate to 90°? (a) a servo motor (b) a motor (c) a buzzer (d) a pump
27. 27.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a wooden stick across the gap. Does the bulb glow? (a) No (b) Yes
28. 28.True or false: a circle with a cross is the symbol for a bulb. (a) False (b) True
29. 29.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a resistor (d) a capacitor
30. 30.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
31. 31.🧮 A 47 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
32. 32.🧩 Which component makes a beeping sound? (a) potentiometer (b) LED (c) buzzer (d) transistor
33. 33.🔍 Which is the odd one out? (a) a dry cork (b) a brass key (c) a rubber eraser (d) a plastic straw
34. 34.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) sound energy (b) movement energy (c) chemical energy (d) light energy
35. 35.🔍 Which is the odd one out? (a) throw cells in a fire (b) climb an electric pole (c) touch a fallen wire (d) take cells out after use
36. 36.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets bigger (c) gets smaller (d) stays the same
37. 37.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 34 °C. What is shown? (a) Warm (b) Hot (c) Cool
38. 38.True or false: a rice cooker mainly gives out heat. (a) False (b) True
39. 39.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) when either is ON (c) never (d) only when both are OFF
40. 40.True or false: to open blinds at sunrise, use a light sensor. (a) True (b) False

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