Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 481 · 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.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
2. 2.⚡ A 9 W device works on 6 V. What current does it take (in amperes)? =
3. 3.📏 How many milliamperes (mA) is 0.75 A?
4. 4.🔍 Which is the odd one out? (a) a motor (b) a motion sensor (c) a speaker (d) an LED
5. 5.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the longer line (c) neither line (d) the shorter line
6. 6.🔍 Which is the odd one out? (a) fly a kite near wires (b) use small battery cells (c) climb an electric pole (d) open a phone charger
7. 7.Which drawing is the symbol for a diode? (a) a circle with V inside (b) triangle against a bar (c) one tall, one short bar (d) a circle with a cross
8. 8.True or false: a plastic straw is an insulator. (a) True (b) False
9. 9.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 0.5 V (c) 1.5 V (d) 230 V
10. 10.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) dotted circles (d) wavy lines
11. 11.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
12. 12.🌈 A resistor has the colour bands blue, grey, brown. What is its value (in ohms)?
13. 13.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a woollen thread across the gap. Does the bulb glow? (a) No (b) Yes
14. 14.🔋 3 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
15. 15.🔍 An object is 323 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
16. 16.True or false: “a knob turned part way” is an analog signal. (a) True (b) False
17. 17.🤖 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
18. 18.🔍 Which is the odd one out? (a) touch a fallen wire (b) throw cells in a fire (c) build with an adult near (d) climb an electric pole
19. 19.True or false: one tall, one short bar is the symbol for a diode. (a) True (b) False
20. 20.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) to make it colourful (c) symbols are heavier (d) quick and clear for all
21. 21.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) make light (d) spin a wheel
22. 22.🌈 In the resistor colour code, which number does brown stand for?
23. 23.🔍 Which sensor would you use to keep an incubator warm? (a) a motion sensor (b) a light sensor (c) a temperature sensor (d) a gas sensor
24. 24.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) no voltage (c) half the voltage (d) the same voltage
25. 25.🤖 Does a wind-up toy usually have a microcontroller inside? (a) Yes (b) No
26. 26.🔋 What is a battery? (a) a kind of bulb (b) a switch with a lid (c) one single wire (d) two or more cells joined
27. 27.🌐 In an IoT system, which part measures the real world? (a) phone app (b) cloud server (c) sensor (d) actuator
28. 28.🔋 8 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)? =
29. 29.⚡ A device works on 1.5 V and takes 0.1 A. What is its power (in watts)? =
30. 30.Which of these gives us electricity? (a) a wind turbine (b) a computer (c) a mobile phone (d) a water pump
31. 31.⏱️ How many milliseconds is a wait of 1.5 seconds?
32. 32.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🧩 Which component makes things spin? (a) capacitor (b) motor (c) LED (d) potentiometer
34. 34.🔌 Is a speaker an input or an output for a microcontroller? (a) output (b) input
35. 35.🔍 Which is the odd one out? (a) a buzzer (b) a light sensor (c) a small display (d) an LED
36. 36.True or false: on a cell, “the flat end” means the − (negative) end. (a) True (b) False
37. 37.Which of these mainly makes sound? (a) a torch (b) a ceiling fan (c) an exhaust fan (d) a loudspeaker
38. 38.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V × R (d) I = V ÷ R
39. 39.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
40. 40.True or false: to take cells out after use is not safe. (a) False (b) True

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