Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 663 · 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.Which job needs a motor? (a) show the temperature (b) move water to plants (c) turn to an exact angle (d) spin a robot’s wheels
2. 2.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
3. 3.🔍 Which is the odd one out? (a) a battery torch (b) a plain wall switch (c) a Wi-Fi doorbell camera (d) a pencil sharpener
4. 4.💡 An LED is joined to a 9 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
5. 5.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = V × I (c) R = I ÷ V (d) R = V ÷ I
6. 6.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) to make them heavy (c) plastic is a conductor (d) plastic makes current
7. 7.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when both are ON (c) when either is ON (d) never
8. 8.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) water carries current (c) it is just untidy (d) it spoils the paint
9. 9.🔘 Which kind of switch works only while pressed? (a) a toggle switch (b) a reed switch (c) a push button (d) a tilt switch
10. 10.🔘 Which kind of switch closes when tipped over? (a) a tilt switch (b) a push button (c) a toggle switch (d) a reed switch
11. 11.True or false: to use a cable with cuts is not safe. (a) False (b) True
12. 12.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
13. 13.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 570 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
14. 14.💡 An LED is joined to a 6 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
15. 15.🔌 Most metals are good … (a) magnets only (b) batteries (c) insulators (d) conductors
16. 16.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) zero (d) smaller
17. 17.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) the size of a cell (d) energy used each second
18. 18.Which of these usually has a microcontroller inside? (a) a spinning top (b) a smart watch (c) a wind-up toy (d) a plain wall switch
19. 19.⚡ What does an electric iron mainly change electricity into? (a) sound (b) light (c) heat (d) movement
20. 20.🔋 5 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
21. 21.True or false: to switch off empty rooms saves electricity. (a) False (b) True
22. 22.True or false: to use daylight to read wastes electricity. (a) True (b) False
23. 23.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
24. 24.🌐 Is a plain table fan an IoT device? (a) an IoT device (b) not an IoT device
25. 25.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Cool (b) Warm (c) Hot
26. 26.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 10 minutes?
27. 27.True or false: a circle with an X in it is the symbol for a capacitor. (a) True (b) False
28. 28.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 90 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
29. 29.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a mains extension board (c) a wall socket (d) a small battery pack
30. 30.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
31. 31.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
32. 32.🔁 count = 5
    while (count < 37) { count = count + 4 }
    How many times does the loop run?
33. 33.Which of these mainly gives out light? (a) a siren (b) a street light (c) a buzzer (d) a school bell
34. 34.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
35. 35.What does the microcontroller do? (a) measures the real world (b) acts on a command (c) carries the data (d) reads values, decides
36. 36.Which of these is a conductor? (a) a plastic ruler (b) a brass key (c) a paper strip (d) a wooden stick
37. 37.True or false: “used in house wiring” is true of a parallel circuit. (a) True (b) False
38. 38.🌈 A resistor has the colour bands white, violet, yellow. What is its value in kilo-ohms (kΩ)? =
39. 39.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
40. 40.🧩 Which component senses how bright it is? (a) LDR (b) capacitor (c) thermistor (d) motor

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