Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 403 · 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 an IoT device? (a) a plain wall switch (b) a Wi-Fi weather station (c) a pencil sharpener (d) a paper calendar
2. 2.🔐 Is it a good or a risky habit to accept every permission? (a) good habit (b) risky habit
3. 3.True or false: triangle, bar and arrows is the symbol for an LED. (a) True (b) False
4. 4.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) stays the same (c) gets bigger (d) becomes zero
5. 5.Which of these gives us electricity? (a) a water pump (b) a solar panel (c) a television (d) a refrigerator
6. 6.🔌 Is a sound sensor an input or an output for a microcontroller? (a) output (b) input
7. 7.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
8. 8.Which of these is measured in watts (W)? (a) the flow of charge (b) energy used each second (c) voltage (d) how much a part resists
9. 9.🔁 total = 0
   for i = 1 to 10 { total = total + i }
   What is total at the end?
10. 10.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
11. 11.⏱️ A program says “wait 4250 ms”. How many seconds is that? =
12. 12.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) unplug idle chargers (c) use LED lamps (d) run fans in empty rooms
13. 13.🔁 repeat 3 times { repeat 3 times { beep } }
    How many beeps are there?
14. 14.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) waits 500 seconds (c) turns the LED off (d) blinks 500 times
15. 15.🌈 A resistor has the colour bands green, red, orange. What is its value in kilo-ohms (kΩ)? =
16. 16.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
17. 17.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
18. 18.🧮 Resistors of 50 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
19. 19.🧮 Resistors of 150 Ω, 68 Ω, 10 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
20. 20.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
21. 21.🔍 Which is the odd one out? (a) compare with a limit (b) the fan starts (c) decide if soil is dry (d) count button presses
22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
23. 23.⚡ What does a torch mainly change electricity into? (a) movement (b) heat (c) light (d) sound
24. 24.True or false: to build with an adult near is safe. (a) True (b) False
25. 25.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
26. 26.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
27. 27.True or false: “an LED lights up” is the output. (a) True (b) False
28. 28.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) share it with friends (c) post it online (d) ask a parent first
29. 29.🔌 Is a ceramic cup a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.🔺 A current of 3 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
31. 31.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
32. 32.🔍 Which is the odd one out? (a) a small display (b) a push button (c) a keypad (d) a motion sensor
33. 33.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) joins two wires (d) measures light
34. 34.🔋 What should you do with used-up cells? (a) bury them in soil (b) throw them in a fire (c) give them for recycling (d) cut them open
35. 35.⏱️ loop forever { LED ON; wait 550 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
36. 36.🔋 6 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
37. 37.⚡ A 48 W device works on 24 V. What current does it take (in amperes)? =
38. 38.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
39. 39.True or false: a laptop uses very little power. (a) False (b) True
40. 40.🌈 A resistor has the colour bands grey, blue, red. What is its value in kilo-ohms (kΩ)? =

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