Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 695 · 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 kind of switch stays where you flip it? (a) a tilt switch (b) a reed switch (c) a push button (d) a toggle switch
2. 2.💡 A red LED uses 2 V and should get 25 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
3. 3.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
4. 4.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a soil moisture sensor (c) a light sensor (d) a gas sensor
5. 5.Which job needs a rain sensor? (a) measure classroom noise (b) close a window in rain (c) open blinds at sunrise (d) switch on lamps at dusk
6. 6.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) plastic is an insulator (c) to make them heavy (d) plastic is a conductor
7. 7.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes
8. 8.🔍 Which is the odd one out? (a) a speaker (b) a buzzer (c) a motor (d) a motion sensor
9. 9.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
10. 10.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the reset button (b) the USB port (c) the voltage regulator (d) the pins
11. 11.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 1.5 V (c) 230 V (d) 15 V
12. 12.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) becomes zero (d) gets smaller
13. 13.🔁 repeat 5 times { repeat 5 times { beep } }
    How many beeps are there?
14. 14.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
15. 15.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
16. 16.🔍 Which sensor would you use to close a window in rain? (a) a light sensor (b) a rain sensor (c) a distance sensor (d) a sound sensor
17. 17.💡 6 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?
18. 18.True or false: “a buzzer beeps” is the output. (a) False (b) True
19. 19.🔍 Which is the odd one out? (a) a woollen thread (b) a rubber band (c) a safety pin (d) a dry cork
20. 20.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) a wire has come loose (d) the switch is ON
21. 21.🔌 Which part of a screwdriver should an electrician hold? (a) the plastic handle (b) the steel shaft (c) the metal tip (d) the bare end
22. 22.🔺 A 2.4 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
23. 23.🔍 Which is the odd one out? (a) the fan starts (b) a button press (c) a light level reading (d) a temperature reading
24. 24.🔁 count = 2
    while (count < 34) { count = count + 4 }
    How many times does the loop run?
25. 25.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
26. 26.True or false: a room heater mainly gives out heat. (a) False (b) True
27. 27.🔍 Which is the odd one out? (a) a traffic signal (b) a torch (c) a school bell (d) an LED lamp
28. 28.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) through a candle (c) over Wi-Fi (d) by post
29. 29.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I × R (c) V = R ÷ I (d) V = I + R
30. 30.Which of these mainly gives out light? (a) a mixer grinder (b) a toaster (c) a traffic signal (d) a loudspeaker
31. 31.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) symbols are heavier (c) quick and clear for all (d) to hide the circuit
32. 32.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one (d) one for each bulb
33. 33.True or false: a water heater mainly gives out light. (a) True (b) False
34. 34.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) an open circuit (c) a short circuit (d) a safe circuit
35. 35.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) not joined (d) in series
36. 36.True or false: to measure classroom noise, use a sound sensor. (a) False (b) True
37. 37.🔌 Is a servo motor an input or an output for a microcontroller? (a) input (b) output
38. 38.🤖 if (light < 300) { lamp ON } else { lamp OFF }
    The light sensor reads 323. What happens? (a) lamp ON (b) lamp OFF
39. 39.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they get dimmer (c) they explode (d) they all go out
40. 40.True or false: to log out of shared phones is a good habit. (a) False (b) True

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