Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 173 · 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.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) pauses for half a second (d) blinks 500 times
2. 2.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) own switch for each bulb (c) a break stops every bulb (d) a single current path
3. 3.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic makes current (c) plastic is an insulator (d) plastic is a conductor
4. 4.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) wavy lines (d) dotted circles
5. 5.Which of these is an input? (a) a sound sensor (b) a buzzer (c) a servo motor (d) an LED
6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
7. 7.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 10 (d) 60
8. 8.🤖 if (temperature > 25) { fan ON } else { fan OFF }
   The temperature sensor reads 28 °C. What happens? (a) fan OFF (b) fan ON
9. 9.True or false: a push button springs back when let go. (a) True (b) False
10. 10.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
11. 11.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
12. 12.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) read the soil sensor (b) switch the pump on/off (c) compare with the limit (d) wait a few seconds
13. 13.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a slide switch (c) a tilt switch (d) a toggle switch
14. 14.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
15. 15.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
16. 16.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 31 °C. What is shown? (a) Warm (b) Cool (c) Hot
17. 17.🔢 To get a sensor reading onto a phone, what comes right after “the board reads it”? (a) it is sent by Wi-Fi (b) the cloud stores it (c) the sensor measures (d) the app shows it
18. 18.True or false: to spot someone walking in, use a motion sensor. (a) True (b) False
19. 19.Which of these mainly gives out heat? (a) an electric toy car (b) a mixer grinder (c) a table fan (d) a room heater
20. 20.Which of these is not safe? (a) fly kites in open fields (b) keep drinks far away (c) throw cells in a fire (d) dry your hands first
21. 21.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
22. 22.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) adds 1 to count (d) takes 1 away
23. 23.🔺 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
24. 24.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 72 Ω resistor? (a) red-violet-black (b) grey-red-black (c) violet-red-brown (d) violet-red-black
25. 25.True or false: an electric toy car mainly makes movement. (a) False (b) True
26. 26.🌐 A weather station sends one reading every 30 seconds. How many readings does it send in 4 minutes?
27. 27.🔋 5 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
28. 28.⚙️ What is an actuator? (a) a battery (b) an output that acts (c) a program (d) a sensor
29. 29.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 40 °C. What is shown? (a) Hot (b) Cool (c) Warm
30. 30.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
31. 31.🔋 Does a washing machine give electricity or use electricity? (a) gives electricity (b) uses electricity
32. 32.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
33. 33.True or false: to stop if a part gets hot is not safe. (a) True (b) False
34. 34.🔍 Which is the odd one out? (a) a siren (b) a toaster (c) an electric iron (d) a water heater
35. 35.Which job needs a motor? (a) open a gate to 90° (b) spin a robot’s wheels (c) move water to plants (d) show a status light
36. 36.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) measure heat (d) spin a wheel
37. 37.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
38. 38.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) an LED (d) a motor
39. 39.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
40. 40.🔁 count = 0
    while (count < 16) { count = count + 2 }
    How many times does the loop run?

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