Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 63 · 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.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
2. 2.🌈 A resistor has the colour bands blue, orange, brown. What is its value (in ohms)?
3. 3.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 42 Ω resistor? (a) green-red-black (b) yellow-red-black (c) red-yellow-black (d) yellow-red-brown
4. 4.💡 Why is house wiring done in parallel? (a) so all go off together (b) each gets full voltage (c) to save copper only (d) to make bulbs dim
5. 5.⚠️ Why must we never touch switches with wet hands? (a) water carries current (b) it spoils the paint (c) it is just untidy (d) water makes it cold
6. 6.🔋 7 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
7. 7.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
8. 8.🔐 Is it a good or a risky habit to set up with a parent? (a) risky habit (b) good habit
9. 9.What does the phone app do? (a) acts on a command (b) reads values, decides (c) stores data online (d) shows data to you
10. 10.Which of these is not safe? (a) fly a kite near wires (b) stop if a part gets hot (c) keep drinks far away (d) stay away from pylons
11. 11.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
12. 12.True or false: a long and a short line is the symbol for a cell. (a) True (b) False
13. 13.🔺 A current of 2.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
15. 15.Which of these gives us electricity? (a) a television (b) a refrigerator (c) a water pump (d) a battery
16. 16.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) symbols are heavier (c) to hide the circuit (d) quick and clear for all
17. 17.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
18. 18.🌈 In the resistor colour code, which number does yellow stand for?
19. 19.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
20. 20.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the one nearest an end (d) the gold band
21. 21.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) prints 1 (d) adds 1 to count
22. 22.Which job needs a temperature sensor? (a) start a fan when hot (b) make a parking alarm (c) stop a robot near walls (d) switch on with a clap
23. 23.🔘 Which kind of switch closes near a magnet? (a) a tilt switch (b) a reed switch (c) a toggle switch (d) a slide switch
24. 24.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
25. 25.True or false: “how loud a sound is” is an analog signal. (a) False (b) True
26. 26.🔋 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)? =
27. 27.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
28. 28.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
29. 29.🤖 “if (A AND B)” is true when … (a) both are false (b) both A and B are true (c) only B is true (d) only A is true
30. 30.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
31. 31.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
32. 32.Which of these is true of a series circuit? (a) own switch for each bulb (b) each gets the full volts (c) one out, the rest glow (d) a break stops every bulb
33. 33.What does the Wi-Fi link do? (a) carries the data (b) acts on a command (c) reads values, decides (d) shows data to you
34. 34.True or false: to install software updates is a risky habit. (a) False (b) True
35. 35.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “switch the pump on/off”? (a) switch the pump on/off (b) compare with the limit
36. 36.🔋 4 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)? =
37. 37.Which of these mainly makes sound? (a) a table fan (b) a rice cooker (c) an electric kettle (d) a buzzer
38. 38.🌐 In an IoT system, which part measures the real world? (a) microcontroller (b) sensor (c) actuator (d) cloud server
39. 39.True or false: to set a strong password is a good habit. (a) True (b) False
40. 40.🌐 Is a Wi-Fi smart plug an IoT device? (a) an IoT device (b) not an IoT device

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