Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 517 · 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.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
2. 2.Which of these saves electricity? (a) use old filament bulbs (b) close the fridge quickly (c) iron one shirt at a time (d) leave the TV on standby
3. 3.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
4. 4.📶 Digital or analog: a door: open or shut? (a) digital (b) analog
5. 5.⚡ A device works on 12 V and takes 3 A. What is its power (in watts)? =
6. 6.🧮 A 10 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
7. 7.True or false: a reed switch slides side to side. (a) True (b) False
8. 8.🧮 A 2.8 V battery is joined to 2 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
9. 9.Which of these is safe? (a) use a cable with cuts (b) poke things in a socket (c) use mains for a project (d) fly kites in open fields
10. 10.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
11. 11.⚡ What do we call a flow of electric charge through a wire? (a) friction (b) sound (c) a magnet (d) electric current
12. 12.🔐 Is it a good or a risky habit to read app permissions? (a) risky habit (b) good habit
13. 13.True or false: the ammeter is joined in series. (a) True (b) False
14. 14.Which of these means the circuit is open? (a) a wire has come loose (b) the loop is complete (c) the switch is ON (d) all wires are joined
15. 15.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
16. 16.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output
17. 17.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 5 minutes?
18. 18.🤖 Does a hand pump usually have a microcontroller inside? (a) Yes (b) No
19. 19.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
20. 20.🔍 Which is the odd one out? (a) an LED lamp (b) a tube light (c) a torch (d) an electric iron
21. 21.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V ÷ R (c) I = V × R (d) I = V + R
22. 22.True or false: a wind-up toy usually has a microcontroller inside. (a) True (b) False
23. 23.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the voltage regulator (b) the main chip (c) the USB port (d) the reset button
24. 24.🔘 Which kind of switch slides side to side? (a) a push button (b) a reed switch (c) a slide switch (d) a toggle switch
25. 25.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 240 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
27. 27.True or false: a glass marble is an insulator. (a) True (b) False
28. 28.📏 Which unit measures energy used each second? (a) ampere (A) (b) watt (W) (c) ohm (Ω) (d) volt (V)
29. 29.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 1.5 V (c) 0.5 V (d) 230 V
30. 30.🔐 Is it a good or a risky habit to install software updates? (a) good habit (b) risky habit
31. 31.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 290 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
32. 32.True or false: to switch off empty rooms saves electricity. (a) True (b) False
33. 33.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
34. 34.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 3 and 6 are taken out of their holders. Does bulb 4 glow? (a) No (b) Yes
35. 35.True or false: voltage is measured in amperes (A). (a) True (b) False
36. 36.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
37. 37.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
38. 38.True or false: a wind-up toy has no microcontroller inside. (a) True (b) False
39. 39.What does a slide switch do? (a) springs back when let go (b) slides side to side (c) stays where you flip it (d) works only while pressed
40. 40.🤖 Does a microwave oven usually have a microcontroller inside? (a) Yes (b) No

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