Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 484 · 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: a line lifted at a gap is the symbol for a motor. (a) True (b) False
2. 2.🌈 Which band is read first on a resistor? (a) the gold band (b) the widest gap (c) the one nearest an end (d) any band
3. 3.🌐 Is a battery torch an IoT device? (a) an IoT device (b) not an IoT device
4. 4.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 3 of the switches are OFF and the rest are ON. How many bulbs glow?
5. 5.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
6. 6.🧮 A 20 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
7. 7.⚡ A device works on 12 V and takes 0.5 A. What is its power (in watts)? =
8. 8.🧮 Resistors of 220 Ω, 50 Ω, 470 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.True or false: a toggle switch closes near a magnet. (a) False (b) True
10. 10.True or false: triangle against a bar is the symbol for a diode. (a) False (b) True
11. 11.🔺 A current of 1 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🧮 A 3.2 V battery is joined to 10 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
13. 13.🔁 repeat 5 times { repeat 5 times { beep } }
    How many beeps are there?
14. 14.Which job needs a motor? (a) turn to an exact angle (b) show a status light (c) spin a robot’s wheels (d) show the temperature
15. 15.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a capacitor (c) a buzzer (d) a diode
16. 16.True or false: a slide switch stays where you flip it. (a) False (b) True
17. 17.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
18. 18.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
19. 19.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) compare with the limit (b) read the soil sensor (c) wait a few seconds (d) switch the pump on/off
20. 20.⏱️ repeat 10 times { buzzer ON; wait 500 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
21. 21.True or false: “a light level reading” is the input. (a) False (b) True
22. 22.💡 4 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. Does bulb 1 glow? (a) No (b) Yes
23. 23.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) the if part (d) neither part
24. 24.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
25. 25.🔍 Which is the odd one out? (a) a plastic ruler (b) a brass key (c) a cotton thread (d) a wooden stick
26. 26.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to store charge (c) to make it brighter (d) to limit the current
27. 27.🔺 A current of 1.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🌈 A resistor has the colour bands red, white, black. What is its value (in ohms)?
29. 29.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
30. 30.Which job needs a temperature sensor? (a) switch on lamps at dusk (b) start a fan when hot (c) open blinds at sunrise (d) make a parking alarm
31. 31.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 284. What happens? (a) lamp ON (b) lamp OFF
32. 32.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 110 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
33. 33.🔍 Which is the odd one out? (a) an exhaust fan (b) a buzzer (c) a table fan (d) an electric toy car
34. 34.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
35. 35.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
36. 36.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
37. 37.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.True or false: a line lifted at a gap is the symbol for a switch. (a) False (b) True
39. 39.True or false: a small empty box is the symbol for a resistor. (a) True (b) False
40. 40.🤖 How does a new program get onto a microcontroller board? (a) drawn with a pen (b) uploaded over USB (c) typed on the chip (d) sent by sound

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