Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 26 · 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.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “it is sent by Wi-Fi”? (a) it is sent by Wi-Fi (b) the sensor measures
2. 2.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) an LED (d) a resistor
3. 3.🔍 Which is the odd one out? (a) a safety pin (b) a metal paper clip (c) a copper wire (d) a glass marble
4. 4.True or false: a digital thermometer usually has a microcontroller inside. (a) True (b) False
5. 5.True or false: a tilt switch flips up or down. (a) False (b) True
6. 6.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) compare with the limit (b) wait a few seconds (c) switch the pump on/off
7. 7.Which drawing is the symbol for a battery? (a) triangle against a bar (b) a long and a short line (c) a small empty box (d) many long-short pairs
8. 8.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 5 % (c) 25 % (d) 50 %
9. 9.Which of these is a conductor? (a) a woollen thread (b) a rubber band (c) a glass marble (d) a safety pin
10. 10.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 550 Ω resistor? (a) green-blue-brown (b) green-green-black (c) green-green-red (d) green-green-brown
11. 11.⏱️ loop forever { LED ON; wait 850 ms; LED OFF; wait 700 ms }
    How many milliseconds does one blink (ON + OFF) take?
12. 12.True or false: to log out of shared phones is a good habit. (a) True (b) False
13. 13.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
14. 14.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
15. 15.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
16. 16.Which job needs a distance sensor? (a) close a window in rain (b) stop a robot near walls (c) warn of a gas leak (d) keep an incubator warm
17. 17.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the else part (b) neither part (c) both parts (d) the if part
18. 18.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) share it with friends (b) post it online (c) ask a parent first (d) type it all in
19. 19.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 5 V supply. What current flows (in mA)?
20. 20.🔍 Which is the odd one out? (a) fly kites in open fields (b) poke things in a socket (c) use a cable with cuts (d) throw cells in a fire
21. 21.🔍 Which is the odd one out? (a) keep drinks far away (b) build with an adult near (c) stay away from pylons (d) touch a switch when wet
22. 22.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
23. 23.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
24. 24.⚡ A 1.8 W device works on 9 V. What current does it take (in amperes)? =
25. 25.🔍 Which is the odd one out? (a) share camera links (b) ignore update messages (c) share the Wi-Fi key (d) change default passwords
26. 26.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) their sum (c) always zero (d) more than either one
27. 27.🔺 A current of 25 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.Which of these is safe? (a) touch a fallen wire (b) poke things in a socket (c) take cells out after use (d) open a phone charger
29. 29.🔍 Which sensor would you use to make a parking alarm? (a) a gas sensor (b) a rain sensor (c) a distance sensor (d) a sound sensor
30. 30.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 2 hours?
31. 31.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
32. 32.True or false: a reed switch closes near a magnet. (a) False (b) True
33. 33.🌐 Is a plain wall switch an IoT device? (a) an IoT device (b) not an IoT device
34. 34.What does a toggle switch do? (a) springs back when let go (b) closes near a magnet (c) stays where you flip it (d) works only while pressed
35. 35.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) makes electricity (c) stores current (d) changes the voltage
36. 36.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) No (b) Yes
37. 37.🔺 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
38. 38.🌐 How does a home IoT device usually send its data to the app? (a) over Wi-Fi (b) by shouting (c) by post (d) through a candle
39. 39.🗺️ In an input → process → output plan, is “a motion sensor signal” the input, the process or the output? (a) output (b) input (c) process
40. 40.True or false: “decide if soil is dry” is the output. (a) True (b) False

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