Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 398 · 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.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) never (c) only when both are ON (d) only when both are OFF
2. 2.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they all go out (c) they keep glowing (d) they get dimmer
3. 3.Which of these gives us electricity? (a) a water pump (b) a wind turbine (c) an air conditioner (d) a computer
4. 4.True or false: a glass marble is an insulator. (a) True (b) False
5. 5.💡 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?
6. 6.🔌 Is a speaker an input or an output for a microcontroller? (a) output (b) input
7. 7.🔺 A current of 2.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
8. 8.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) waits 500 seconds (d) blinks 500 times
9. 9.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) never (c) when both are ON (d) when either is ON
10. 10.⚡ A 6 W device works on 6 V. What current does it take (in amperes)? =
11. 11.⚙️ Which actuator would you use to show the temperature? (a) a display (b) a motor (c) a pump (d) a servo motor
12. 12.🔁 count = 1
    while (count < 13) { count = count + 4 }
    How many times does the loop run?
13. 13.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
14. 14.🔁 count = 5
    repeat 9 times { count = count + 2 }
    What is count at the end?
15. 15.🔍 Which sensor would you use to stop a robot near walls? (a) a motion sensor (b) a distance sensor (c) a temperature sensor (d) a sound sensor
16. 16.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the else part (b) the if part (c) both parts (d) neither part
17. 17.True or false: a circle with an X in it is the symbol for a bulb. (a) False (b) True
18. 18.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 52. What happens? (a) lamp ON (b) lamp OFF
19. 19.🔌 Is a keypad an input or an output for a microcontroller? (a) input (b) output
20. 20.What does a toggle switch do? (a) works only while pressed (b) closes near a magnet (c) closes when tipped over (d) stays where you flip it
21. 21.⚙️ What is an actuator? (a) a program (b) an output that acts (c) a battery (d) a sensor
22. 22.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a small battery pack (c) a mains extension board (d) a wall socket
23. 23.Which job needs a rain sensor? (a) switch on lamps at dusk (b) open blinds at sunrise (c) keep an incubator warm (d) close a window in rain
24. 24.🤖 Which is a safe power source for a beginner microcontroller board? (a) USB or a 9 V battery (b) bare mains wires (c) a 230 V cable (d) a wall socket directly
25. 25.True or false: to reuse one password is a good habit. (a) False (b) True
26. 26.Which of these has no microcontroller inside? (a) a toy robot (b) a digital alarm clock (c) a washing machine (d) a wind-up toy
27. 27.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
28. 28.📏 Voltmeter or ammeter: which one is joined in series? (a) ammeter (b) voltmeter
29. 29.🌈 A resistor has the colour bands grey, brown, black. What is its value (in ohms)?
30. 30.Which of these is safe? (a) poke things in a socket (b) touch a switch when wet (c) stay away from pylons (d) throw cells in a fire
31. 31.⚡ A device works on 12 V and takes 0.1 A. What is its power (in watts)? =
32. 32.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) battery (b) ammeter (c) diode (d) resistor
33. 33.Which drawing is the symbol for a bulb? (a) a circle with M inside (b) triangle, bar and arrows (c) a circle with a cross (d) a dot where wires meet
34. 34.💡 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) Yes (b) No
35. 35.⚙️ Which actuator would you use to show a status light? (a) a pump (b) a motor (c) an LED (d) a display
36. 36.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
37. 37.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 3 seconds?
38. 38.⏱️ A program says “wait 6750 ms”. How many seconds is that? =
39. 39.🔋 Does a washing machine give electricity or use electricity? (a) uses electricity (b) gives electricity
40. 40.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a diode (c) a capacitor (d) a buzzer

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