Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 33 · 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 of these is a risky habit? (a) cover unused cameras (b) turn off unused gadgets (c) change default passwords (d) ignore update messages
2. 2.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
3. 3.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) risky habit (b) good habit
4. 4.🔋 Does an air conditioner give electricity or use electricity? (a) uses electricity (b) gives electricity
5. 5.True or false: “the pump turns on” is the output. (a) False (b) True
6. 6.⚡ What does a tube light mainly change electricity into? (a) light (b) sound (c) heat (d) movement
7. 7.Which of these is a good habit? (a) reuse one password (b) read app permissions (c) accept every permission (d) ignore update messages
8. 8.💡 4 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
9. 9.🌈 A resistor has the colour bands yellow, brown, red. What is its value (in ohms)?
10. 10.⚡ A device works on 5 V and takes 0.2 A. What is its power (in watts)? =
11. 11.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) wavy lines (c) little stars (d) straight lines
12. 12.🧮 Resistors of 10 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?
13. 13.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the board reads it”? (a) the board reads it (b) the app shows it
14. 14.🔍 Which is the odd one out? (a) an LED (b) a small display (c) a servo motor (d) a light sensor
15. 15.🔺 A current of 50 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) zero (c) smaller (d) stay the same
17. 17.⚡ A 2.4 W device works on 12 V. What current does it take (in amperes)? =
18. 18.True or false: a circle with V inside is the symbol for a bulb. (a) False (b) True
19. 19.📏 Which unit measures power? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
20. 20.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it does not light (c) it makes a sound (d) it changes colour
21. 21.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) measures light (d) blinks an LED
22. 22.🔺 A 4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
23. 23.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
24. 24.Which job needs a pump? (a) beep an alarm (b) spin a robot’s wheels (c) show a status light (d) move water to plants
25. 25.True or false: “own switch for each bulb” is true of a series circuit. (a) True (b) False
26. 26.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
27. 27.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
28. 28.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a metal paper clip across the gap. Does the bulb glow? (a) Yes (b) No
29. 29.⚡ A device works on 6 V and takes 0.25 A. What is its power (in watts)? =
30. 30.True or false: to unplug idle chargers saves electricity. (a) False (b) True
31. 31.Which of these is a good habit? (a) reuse one password (b) accept every permission (c) share camera links (d) share only needed data
32. 32.🌐 Is a paper calendar an IoT device? (a) not an IoT device (b) an IoT device
33. 33.⚡ A 13.5 W device works on 9 V. What current does it take (in amperes)? =
34. 34.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the cloud stores it”? (a) the app shows it (b) the cloud stores it
35. 35.Which of these mainly gives out light? (a) a toaster (b) an LED lamp (c) a water heater (d) a ceiling fan
36. 36.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
37. 37.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) type it all in (c) share it with friends (d) ask a parent first
38. 38.🔘 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 OFF, B is OFF and C is ON. Does the bulb glow? (a) Yes (b) No
39. 39.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
40. 40.Which of these is not an IoT device? (a) a paper calendar (b) a smart energy meter (c) a Wi-Fi doorbell camera (d) a Wi-Fi weather station

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