Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 14 · 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: how much a part resists is measured in watts (W). (a) True (b) False
2. 2.⚡ What does a tube light mainly change electricity into? (a) movement (b) light (c) sound (d) heat
3. 3.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the sensor measures (b) the board reads it (c) it is sent by Wi-Fi (d) the app shows it
4. 4.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
5. 5.What does a reed switch do? (a) works only while pressed (b) slides side to side (c) springs back when let go (d) closes near a magnet
6. 6.Which drawing is the symbol for a cell? (a) a long and a short line (b) a circle with A inside (c) triangle against a bar (d) two or more cell symbols
7. 7.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 1000 ms }
   How many milliseconds does one blink (ON + OFF) take?
8. 8.🔐 Is it a good or a risky habit to reuse one password? (a) risky habit (b) good habit
9. 9.🔺 A 9 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
10. 10.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) capacitor (b) resistor (c) diode (d) switch
11. 11.⚠️ Is it safe to fly kites in open fields? (a) not safe (b) safe
12. 12.Which job needs a soil moisture sensor? (a) keep an incubator warm (b) water a dry plant (c) measure classroom noise (d) spot someone walking in
13. 13.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
14. 14.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 6 minutes?
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
16. 16.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 32 °C. What is shown? (a) Warm (b) Cool (c) Hot
17. 17.Which drawing is the symbol for a battery? (a) a plain rectangle (b) a circle with A inside (c) a circle with M inside (d) two or more cell symbols
18. 18.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 170 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
19. 19.🔐 Is it a good or a risky habit to read app permissions? (a) good habit (b) risky habit
20. 20.🔺 A current of 10 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
21. 21.🔌 Is a motion sensor an input or an output for a microcontroller? (a) input (b) output
22. 22.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) wire (b) battery (c) LED (d) diode
23. 23.Which of these gives us electricity? (a) a water pump (b) a washing machine (c) a television (d) a solar panel
24. 24.🔐 Privacy for a smart device means controlling … (a) who can see your data (b) its battery size (c) how loud it beeps (d) its colour
25. 25.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
26. 26.🔌 Is a water pump an input or an output for a microcontroller? (a) input (b) output
27. 27.True or false: to keep an incubator warm, use a light sensor. (a) True (b) False
28. 28.🔘 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
29. 29.💡 2 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
30. 30.🧩 Which component smooths a wobbly supply? (a) potentiometer (b) capacitor (c) fuse (d) LDR
31. 31.Which of these gives us electricity? (a) an air conditioner (b) a refrigerator (c) a battery (d) a mobile phone
32. 32.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
33. 33.🔢 To get a sensor reading onto a phone, which comes first: “it is sent by Wi-Fi” or “the cloud stores it”? (a) it is sent by Wi-Fi (b) the cloud stores it
34. 34.🔺 A current of 2.5 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I ÷ R (d) V = I × R
36. 36.🔺 A current of 40 mA flows when 8.8 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 50 % (d) 5 %
38. 38.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
39. 39.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) more than either one (c) always zero (d) their sum
40. 40.Which of these is an IoT device? (a) a plain table fan (b) a Wi-Fi weather station (c) a battery torch (d) a plain wall switch

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