Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 731 · 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.🤖 “if (A AND B)” is true when … (a) only A is true (b) only B is true (c) both A and B are true (d) both are false
2. 2.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
   How many times does the LED blink in 4 seconds?
3. 3.True or false: the ammeter is joined in series. (a) True (b) False
4. 4.⏱️ repeat 5 times { buzzer ON; wait 500 ms; buzzer OFF; wait 600 ms }
   How many milliseconds does this take in all?
5. 5.🌈 A resistor has the colour bands red, black, red. What is its value (in ohms)?
6. 6.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the bare end (c) the plastic handle (d) the metal tip
7. 7.🤖 Which is a safe power source for a beginner microcontroller board? (a) bare mains wires (b) a 230 V cable (c) USB or a 9 V battery (d) a wall socket directly
8. 8.🔌 Which metal is used for most electric wires at home? (a) plastic (b) glass (c) rubber (d) copper
9. 9.⚡ What does a ceiling fan mainly change electricity into? (a) sound (b) heat (c) movement (d) light
10. 10.Which of these mainly gives out heat? (a) an electric toy car (b) a mixer grinder (c) a toaster (d) a doorbell
11. 11.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
12. 12.⚡ What does a school bell mainly change electricity into? (a) light (b) movement (c) sound (d) heat
13. 13.🔐 Which is the strongest password for a home smart camera? (a) Tiger#Lamp42!Moon (b) 123456 (c) admin (d) password
14. 14.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 509. What happens? (a) lamp ON (b) lamp OFF
15. 15.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 6 glow? (a) No (b) Yes
16. 16.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
18. 18.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 25 % (d) 0 %
19. 19.Which of these is the input? (a) a buzzer beeps (b) decide if soil is dry (c) check if temp > 30 (d) a temperature reading
20. 20.⏱️ loop forever { LED ON; wait 750 ms; LED OFF; wait 500 ms }
    How many milliseconds does one blink (ON + OFF) take?
21. 21.🔍 Which is the odd one out? (a) a light sensor (b) a motor (c) a motion sensor (d) a turning knob
22. 22.🌈 In the resistor colour code, which number does orange stand for?
23. 23.💡 An LED is joined to a 9 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
24. 24.🌈 A resistor has the colour bands violet, yellow, orange. What is its value in kilo-ohms (kΩ)? =
25. 25.🔺 A current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
26. 26.📶 A pin set LOW gives about … (a) 1.5 V (b) 5 V (c) 0 V (d) 9 V
27. 27.True or false: to make a parking alarm, use a rain sensor. (a) True (b) False
28. 28.🌐 In an IoT system, which part carries the data? (a) actuator (b) Wi-Fi (c) sensor (d) microcontroller
29. 29.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “read the soil sensor”? (a) compare with the limit (b) read the soil sensor
30. 30.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
31. 31.Which of these is an output? (a) a speaker (b) a sound sensor (c) a temperature sensor (d) a light sensor
32. 32.🔍 Which is the odd one out? (a) a buzzer beeps (b) a motion sensor signal (c) the pump turns on (d) an LED lights up
33. 33.🗺️ Before building a project, what should you write down first? (a) the final price (b) the box colour (c) inputs and outputs (d) nothing at all
34. 34.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
35. 35.True or false: “the room temperature” is a digital signal. (a) False (b) True
36. 36.🔋 A 3 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
37. 37.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 100 (d) 10
38. 38.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
39. 39.True or false: a slide switch flips up or down. (a) True (b) False
40. 40.Which of these is not an IoT device? (a) a Wi-Fi doorbell camera (b) a paper calendar (c) a Wi-Fi smart plug (d) an app-controlled bulb

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