Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 389 · 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.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a copper wire across the gap. Does the bulb glow? (a) No (b) Yes
2. 2.True or false: a toggle switch slides side to side. (a) True (b) False
3. 3.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 250 ms }
   How many milliseconds does one blink (ON + OFF) take?
4. 4.⚠️ Is it safe to open a phone charger? (a) safe (b) not safe
5. 5.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
6. 6.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a diode (c) a resistor (d) a buzzer
7. 7.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) False (b) True
8. 8.⏱️ A program says “wait 2000 ms”. How many seconds is that? =
9. 9.Which of these has no microcontroller inside? (a) a plain wall switch (b) a smart watch (c) a washing machine (d) a TV remote
10. 10.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in parallel (c) not joined (d) in series
11. 11.🌈 A resistor has the colour bands violet, grey, red. What is its value (in ohms)?
12. 12.True or false: to stop a robot near walls, use a light sensor. (a) True (b) False
13. 13.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
14. 14.🔍 Which is the odd one out? (a) take cells out after use (b) use a cable with cuts (c) touch a fallen wire (d) use mains for a project
15. 15.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
16. 16.True or false: a laptop has no screen of its own. (a) True (b) False
17. 17.⚡ A device works on 5 V and takes 0.25 A. What is its power (in watts)? =
18. 18.True or false: “many values in a range” is an analog signal. (a) False (b) True
19. 19.True or false: a ceiling fan mainly makes movement. (a) False (b) True
20. 20.🔘 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 ON and C is OFF. Does the bulb glow? (a) Yes (b) No
21. 21.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
22. 22.Which of these is the process? (a) compare with a limit (b) an alert on the phone (c) an LED lights up (d) a soil moisture reading
23. 23.🌈 In the resistor colour code, which number does black stand for?
24. 24.🧩 A capacitor in a circuit can … (a) spin a wheel (b) measure heat (c) store charge briefly (d) make light
25. 25.What does a diode do? (a) turns a fan or wheels (b) makes a beeping sound (c) lets current go one way (d) stores a little charge
26. 26.True or false: the ammeter is joined across a part. (a) False (b) True
27. 27.🔦 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) No (b) Yes
28. 28.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
29. 29.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) a power source (c) a fuse (d) an output
30. 30.🔐 Is it a good or a risky habit to reuse one password? (a) risky habit (b) good habit
31. 31.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 3 hours?
32. 32.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
33. 33.🔋 Does a television give electricity or use electricity? (a) gives electricity (b) uses electricity
34. 34.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 100 (d) 10
35. 35.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to an 8 V supply. What current flows (in mA)?
36. 36.What does a potentiometer do? (a) turns a fan or wheels (b) smooths a wobbly supply (c) stores a little charge (d) is a resistance knob
37. 37.True or false: a brass key is a conductor. (a) True (b) False
38. 38.What does a resistor do? (a) makes a beeping sound (b) makes things spin (c) senses how hot it is (d) limits the current
39. 39.💡 What does LED stand for? (a) large electric dial (b) low energy device (c) light-emitting diode (d) light energy dial
40. 40.🔘 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 OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No

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