Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 829 · 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.True or false: a circle with an X in it is the symbol for a bulb. (a) True (b) False
2. 2.🔌 Is a steel spoon a conductor or an insulator? (a) a conductor (b) an insulator
3. 3.🔺 A current of 1.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
4. 4.⚠️ Is it safe to climb an electric pole? (a) not safe (b) safe
5. 5.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) prints 1 (c) sets count to 1 (d) takes 1 away
6. 6.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
7. 7.Which of these saves electricity? (a) iron one shirt at a time (b) use daylight to read (c) use old filament bulbs (d) leave fridge door open
8. 8.💡 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?
9. 9.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) the switch is OFF (d) a wire has come loose
10. 10.🔍 Which is the odd one out? (a) a brass key (b) a copper wire (c) aluminium foil (d) a cotton thread
11. 11.🔍 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
12. 12.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) it is sent by Wi-Fi (b) the board reads it (c) the sensor measures (d) the app shows it
13. 13.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
14. 14.🔢 To run one loop of a plant-watering program, which comes first: “wait a few seconds” or “read the soil sensor”? (a) wait a few seconds (b) read the soil sensor
15. 15.True or false: aluminium foil is a conductor. (a) False (b) True
16. 16.True or false: a laptop has a built-in keyboard. (a) True (b) False
17. 17.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
18. 18.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
19. 19.Which drawing is the symbol for a capacitor? (a) two or more cell symbols (b) a small empty box (c) triangle against a bar (d) two equal parallel lines
20. 20.What does a fuse do? (a) has coloured bands (b) senses how bright it is (c) blows if current is high (d) senses how hot it is
21. 21.🌐 In an IoT system, which part measures the real world? (a) sensor (b) cloud server (c) phone app (d) Wi-Fi
22. 22.🌈 A resistor has the colour bands red, yellow, orange. What is its value in kilo-ohms (kΩ)? =
23. 23.Which of these is an input? (a) a water pump (b) a sound sensor (c) a small display (d) a speaker
24. 24.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 0.5 V (c) 1.5 V (d) 230 V
25. 25.⚡ What do we call a flow of electric charge through a wire? (a) electric current (b) friction (c) a magnet (d) sound
26. 26.True or false: to climb an electric pole is safe. (a) False (b) True
27. 27.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
28. 28.Which of these uses electricity? (a) a battery (b) a bicycle dynamo (c) a generator (d) an air conditioner
29. 29.🔌 Is a turning knob an input or an output for a microcontroller? (a) output (b) input
30. 30.🔌 Is a rubber eraser a conductor or an insulator? (a) a conductor (b) an insulator
31. 31.True or false: a reed switch closes near a magnet. (a) True (b) False
32. 32.🔺 A current of 0.2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
33. 33.True or false: a buzzer senses how hot it is. (a) True (b) False
34. 34.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V × R (c) I = V ÷ R (d) I = R ÷ V
35. 35.True or false: to close a window in rain, use a distance sensor. (a) False (b) True
36. 36.Which of these is measured in amperes (A)? (a) how much a part resists (b) voltage (c) the push of a cell (d) the flow of charge
37. 37.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
38. 38.🔺 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
39. 39.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) a parent or guardian (c) an online stranger (d) nobody at all
40. 40.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) the else part (d) neither part

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