Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 538 · 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 is the odd one out? (a) a Wi-Fi doorbell camera (b) a pencil sharpener (c) a Wi-Fi smart plug (d) an app-controlled bulb
2. 2.🔋 Does a computer give electricity or use electricity? (a) uses electricity (b) gives electricity
3. 3.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 1 minute?
4. 4.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) to make them heavy (c) plastic makes current (d) plastic is a conductor
5. 5.🔺 A current of 2.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
6. 6.🌐 Is an app-controlled bulb an IoT device? (a) not an IoT device (b) an IoT device
7. 7.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) who can see your data (d) how loud it beeps
8. 8.⚙️ Which actuator would you use to beep an alarm? (a) an LED (b) a display (c) a buzzer (d) a servo motor
9. 9.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) tell it your passwords (b) put it in the bathroom (c) let strangers use it (d) mute it when not in use
10. 10.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
11. 11.✏️ In a circuit diagram, which part is drawn as a straight line? (a) voltmeter (b) motor (c) resistor (d) wire
12. 12.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) gets bigger (d) becomes zero
13. 13.⚡ What does a rice cooker mainly change electricity into? (a) light (b) sound (c) movement (d) heat
14. 14.True or false: a cotton thread is an insulator. (a) False (b) True
15. 15.🔺 A current of 25 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🔐 Is it a good or a risky habit to ignore update messages? (a) good habit (b) risky habit
17. 17.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “list inputs and outputs”? (a) list inputs and outputs (b) pick a problem to solve
18. 18.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a wind-up clock (c) a battery torch (d) a pencil sharpener
19. 19.True or false: a circle with V inside is the symbol for a voltmeter. (a) False (b) True
20. 20.🧮 A 33 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
21. 21.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
22. 22.🤖 “if (A AND B)” is true when … (a) only B is true (b) only A is true (c) both are false (d) both A and B are true
23. 23.🧮 A 2.8 V battery is joined to 12 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
24. 24.📶 A pin set LOW gives about … (a) 9 V (b) 0 V (c) 1.5 V (d) 5 V
25. 25.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) No (b) Yes
27. 27.🔋 What is a battery? (a) a switch with a lid (b) two or more cells joined (c) a kind of bulb (d) one single wire
28. 28.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a smaller voltage (c) the same voltage (d) a bigger voltage
29. 29.🔁 count = 5
    while (count < 30) { count = count + 5 }
    How many times does the loop run?
30. 30.🌈 A resistor has the colour bands white, violet, brown. What is its value (in ohms)?
31. 31.⏱️ How many milliseconds is a wait of 3.5 seconds?
32. 32.True or false: to accept every permission is a good habit. (a) True (b) False
33. 33.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
34. 34.💡 An LED is joined to a 6 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
35. 35.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
36. 36.🔍 Which is the odd one out? (a) stop if a part gets hot (b) stay away from pylons (c) poke things in a socket (d) build with an adult near
37. 37.🤖 What is a microcontroller? (a) a big desktop computer (b) a kind of bulb (c) a computer on one chip (d) a type of battery
38. 38.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
39. 39.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 38 °C. What is shown? (a) Hot (b) Warm (c) Cool
40. 40.Which of these is an input? (a) a servo motor (b) a small display (c) a buzzer (d) a motion sensor

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