Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 84 · 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.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) one (c) none (d) two
2. 2.🔘 Which kind of switch works only while pressed? (a) a tilt switch (b) a push button (c) a reed switch (d) a slide switch
3. 3.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
4. 4.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) an LED (d) a resistor
5. 5.🔍 Which is the odd one out? (a) a water pump (b) a turning knob (c) a servo motor (d) a motor
6. 6.🔁 repeat 4 times { repeat 2 times { beep } }
   How many beeps are there?
7. 7.🌈 A resistor has the colour bands orange, grey, brown. What is its value (in ohms)?
8. 8.True or false: to use old filament bulbs saves electricity. (a) True (b) False
9. 9.⚡ What does a toaster mainly change electricity into? (a) movement (b) light (c) heat (d) sound
10. 10.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
11. 11.⚙️ Which actuator would you use to open a gate to 90°? (a) an LED (b) a pump (c) a motor (d) a servo motor
12. 12.💡 5 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
13. 13.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
14. 14.🔁 repeat 4 times { repeat 6 times { beep } }
    How many beeps are there?
15. 15.🤖 Does a smart watch usually have a microcontroller inside? (a) Yes (b) No
16. 16.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
17. 17.🔍 Which is the odd one out? (a) a steel coin (b) a steel spoon (c) a plastic ruler (d) an iron nail
18. 18.🔋 What is a battery? (a) two or more cells joined (b) a kind of bulb (c) one single wire (d) a switch with a lid
19. 19.🔺 A current of 50 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
20. 20.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
21. 21.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 50 Ω resistor? (a) blue-black-black (b) green-black-black (c) blue-green-black (d) green-black-brown
22. 22.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) voltmeter (b) bulb (c) motor (d) ammeter
23. 23.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) always zero (c) less than either one (d) their sum
24. 24.🌐 In an IoT system, which part measures the real world? (a) cloud server (b) sensor (c) microcontroller (d) Wi-Fi
25. 25.What does a diode do? (a) lets current go one way (b) beeps for an alarm (c) makes a beeping sound (d) has coloured bands
26. 26.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
27. 27.🤖 Does a wind-up toy usually have a microcontroller inside? (a) No (b) Yes
28. 28.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
29. 29.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
30. 30.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) No (b) Yes
31. 31.Which of these is safe? (a) use small battery cells (b) use mains for a project (c) fly a kite near wires (d) open a phone charger
32. 32.⚡ A device works on 1.5 V and takes 0.1 A. What is its power (in watts)? =
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a metal paper clip across the gap. Does the bulb glow? (a) Yes (b) No
34. 34.💡 An LED is joined to a 9 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
35. 35.🌈 In the resistor colour code, which number does green stand for?
36. 36.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
37. 37.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
38. 38.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) a single current path (c) own switch for each bulb (d) bulbs share the voltage
39. 39.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Warm (b) Hot (c) Cool
40. 40.True or false: to water a dry plant, use a soil moisture sensor. (a) True (b) False

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