Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 705 · 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 tilt switch do? (a) closes when tipped over (b) closes near a magnet (c) slides side to side (d) stays where you flip it
2. 2.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) both lines (c) the longer line (d) the shorter line
3. 3.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   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
4. 4.True or false: “a single current path” is true of a series circuit. (a) False (b) True
5. 5.🔐 Is it a good or a risky habit to reuse one password? (a) good habit (b) risky habit
6. 6.📏 Which unit measures voltage? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
7. 7.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) gets smaller (d) becomes zero
8. 8.⚡ A device works on 1.5 V and takes 0.1 A. What is its power (in watts)? =
9. 9.🔺 A 2.4 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
10. 10.🔘 Which kind of switch flips up or down? (a) a tilt switch (b) a toggle switch (c) a slide switch (d) a reed switch
11. 11.🧮 Resistors of 20 Ω, 33 Ω, 20 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
12. 12.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
13. 13.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
14. 14.🔋 A 9 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
15. 15.🔁 What does a variable do in a program? (a) stores a value (b) joins two wires (c) blinks an LED (d) measures light
16. 16.True or false: the ammeter is joined in series. (a) True (b) False
17. 17.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the input (c) the battery (d) the process
18. 18.True or false: to use old filament bulbs saves electricity. (a) True (b) False
19. 19.What does a motor do? (a) has coloured bands (b) makes things spin (c) makes a beeping sound (d) senses how bright it is
20. 20.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
21. 21.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
22. 22.True or false: a microcontroller has no screen of its own. (a) False (b) True
23. 23.🔺 A 6 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
24. 24.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
25. 25.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 49. What happens? (a) green LED ON (b) red LED ON
26. 26.What does a slide switch do? (a) stays where you flip it (b) slides side to side (c) works only while pressed (d) flips up or down
27. 27.🔍 Which is the odd one out? (a) run fans in empty rooms (b) close the fridge quickly (c) iron one shirt at a time (d) leave fridge door open
28. 28.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) over Wi-Fi (c) by post (d) through a candle
29. 29.True or false: to post your live location is a risky habit. (a) True (b) False
30. 30.🔢 To plan an electronics project, which comes first: “build it with an adult” or “draw the circuit diagram”? (a) build it with an adult (b) draw the circuit diagram
31. 31.💡 4 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?
32. 32.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) put it in the bathroom (b) let strangers use it (c) tell it your passwords (d) mute it when not in use
33. 33.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
34. 34.Which of these is an output? (a) a sound sensor (b) a temperature sensor (c) a servo motor (d) a turning knob
35. 35.🧮 A 20 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
36. 36.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) two (c) none (d) one
37. 37.🔍 Which is the odd one out? (a) a soil moisture reading (b) a button press (c) count button presses (d) a temperature reading
38. 38.🔋 5 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
39. 39.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 21 °C. What is shown? (a) Warm (b) Cool (c) Hot
40. 40.⚡ Which formula gives electric power? (a) P = V × I (b) P = V ÷ I (c) P = V + I (d) P = I ÷ V

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