Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 973 · 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 a push button do? (a) closes when tipped over (b) slides side to side (c) closes near a magnet (d) works only while pressed
2. 2.🧮 Three equal 60 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.🧮 Resistors of 33 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
4. 4.⚡ What does an electric toy car mainly change electricity into? (a) heat (b) movement (c) light (d) sound
5. 5.⏱️ A program says “wait 1750 ms”. How many seconds is that? =
6. 6.🧮 A 2.2 V battery is joined to 5 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
7. 7.⚡ A device works on 24 V and takes 0.25 A. What is its power (in watts)? =
8. 8.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
9. 9.True or false: “a button: pressed or not” is an analog signal. (a) False (b) True
10. 10.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the colour of light (d) the length of a wire
11. 11.True or false: to tap unknown app links is a risky habit. (a) True (b) False
12. 12.⚡ A 72 W device works on 24 V. What current does it take (in amperes)? =
13. 13.🌈 A resistor has the colour bands blue, red, orange. What is its value in kilo-ohms (kΩ)? =
14. 14.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
15. 15.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) never (c) when both are ON (d) when both are OFF
16. 16.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) quick and clear for all (c) to make it colourful (d) to hide the circuit
17. 17.True or false: to touch a switch when wet is safe. (a) False (b) True
18. 18.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
19. 19.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 140 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
20. 20.Which of these is an output? (a) a push button (b) a temperature sensor (c) a turning knob (d) an LED
21. 21.💡 3 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
22. 22.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “it is sent by Wi-Fi”? (a) it is sent by Wi-Fi (b) the sensor measures
23. 23.🔍 Which is the odd one out? (a) a night lamp (b) a tube light (c) a street light (d) a toaster
24. 24.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 25 % (d) 0 %
25. 25.Which of these saves electricity? (a) use daylight to read (b) leave the TV on standby (c) run fans in empty rooms (d) use old filament bulbs
26. 26.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
27. 27.⚡ A device works on 6 V and takes 0.5 A. What is its power (in watts)? =
28. 28.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
29. 29.Which job needs a light sensor? (a) spot someone walking in (b) warn of a gas leak (c) keep an incubator warm (d) open blinds at sunrise
30. 30.🔌 Most metals are good … (a) magnets only (b) conductors (c) insulators (d) batteries
31. 31.🔐 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) mute it when not in use (d) let strangers use it
32. 32.🌐 What does IoT stand for? (a) Input of Tools (b) Internet of Talk (c) Internet of Things (d) Inside of Toys
33. 33.Which job needs a light sensor? (a) switch on lamps at dusk (b) water a dry plant (c) spot someone walking in (d) measure classroom noise
34. 34.True or false: a toggle switch closes when tipped over. (a) True (b) False
35. 35.🔺 A 15 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
36. 36.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 10 (d) 100
37. 37.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
38. 38.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
39. 39.🔺 An 18.8 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
40. 40.True or false: a washing machine has no microcontroller inside. (a) False (b) True

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