Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 425 · 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.⏱️ loop forever { LED ON; wait 550 ms; LED OFF; wait 600 ms }
   How many milliseconds does one blink (ON + OFF) take?
2. 2.🔌 Is a plastic straw a conductor or an insulator? (a) an insulator (b) a conductor
3. 3.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) switch (b) cell (c) battery (d) motor
4. 4.True or false: a straight line is the symbol for a diode. (a) True (b) False
5. 5.📏 How many ohms (Ω) is 1.5 kΩ?
6. 6.What does a fuse do? (a) blows if current is high (b) smooths a wobbly supply (c) lets current go one way (d) makes things spin
7. 7.🔌 Is a sound sensor an input or an output for a microcontroller? (a) output (b) input
8. 8.True or false: a toggle switch stays where you flip it. (a) True (b) False
9. 9.📏 Voltmeter or ammeter: which one is joined in series? (a) voltmeter (b) ammeter
10. 10.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
11. 11.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the process (c) the output (d) the battery
12. 12.🔍 Which is the odd one out? (a) a room heater (b) an electric kettle (c) a water heater (d) a buzzer
13. 13.🔍 Which sensor would you use to warn of a gas leak? (a) a gas sensor (b) a soil moisture sensor (c) a light sensor (d) a motion sensor
14. 14.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
15. 15.🔺 A current of 0.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
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: “how loud a sound is” is a digital signal. (a) False (b) True
18. 18.🌐 A weather station sends one reading every 15 seconds. How many readings does it send in 8 minutes?
19. 19.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.⚡ A 1.8 W device works on 9 V. What current does it take (in amperes)? =
21. 21.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
22. 22.🔺 A current of 1.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔋 7 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
24. 24.Which of these is a good habit? (a) post your live location (b) accept every permission (c) share only needed data (d) share camera links
25. 25.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) Yes (b) No
26. 26.🤖 How does a new program get onto a microcontroller board? (a) sent by sound (b) uploaded over USB (c) typed on the chip (d) drawn with a pen
27. 27.💡 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?
28. 28.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
29. 29.True or false: aluminium foil is an insulator. (a) True (b) False
30. 30.🔢 To plan an electronics project, what comes right after “pick a problem to solve”? (a) list inputs and outputs (b) draw the circuit diagram (c) test it and fix it (d) build it with an adult
31. 31.🔍 Which is the odd one out? (a) a rubber band (b) a dry cork (c) a ceramic cup (d) a steel spoon
32. 32.True or false: a ceramic cup is a conductor. (a) False (b) True
33. 33.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
34. 34.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
35. 35.🔍 Which is the odd one out? (a) share only needed data (b) share the Wi-Fi key (c) set a strong password (d) install software updates
36. 36.🔁 count = 3
    repeat 9 times { count = count + 7 }
    What is count at the end?
37. 37.🔺 A current of 0.25 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
38. 38.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 6 seconds?
39. 39.🔁 count = 3
    while (count < 23) { count = count + 4 }
    How many times does the loop run?
40. 40.🔍 Which is the odd one out? (a) leave the TV on standby (b) close the fridge quickly (c) run fans in empty rooms (d) leave fridge door open

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