Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 960 · 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 a good or a risky habit to reuse one password? (a) risky habit (b) good habit
2. 2.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
3. 3.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they explode (c) they keep glowing (d) they all go out
4. 4.🔁 total = 0
   for i = 1 to 11 { total = total + i }
   What is total at the end?
5. 5.Which of these is an output? (a) a sound sensor (b) a motion sensor (c) a turning knob (d) a servo motor
6. 6.True or false: to unplug idle chargers saves electricity. (a) True (b) False
7. 7.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
   The temperature is 31 °C. What is shown? (a) Cool (b) Warm (c) Hot
8. 8.True or false: a push button closes near a magnet. (a) False (b) True
9. 9.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
10. 10.🔁 repeat 5 times { repeat 5 times { beep } }
    How many beeps are there?
11. 11.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
12. 12.🔐 Why install updates on IoT devices? (a) they fix security holes (b) they change the colour (c) they delete the Wi-Fi (d) they make it heavier
13. 13.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) the else part (d) both parts
14. 14.🔍 Which is the odd one out? (a) a water heater (b) a table fan (c) a toaster (d) an electric iron
15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
16. 16.True or false: a digital thermometer has no microcontroller inside. (a) True (b) False
17. 17.💡 2 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 1 and 2 are taken out of their holders. How many bulbs glow?
18. 18.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
19. 19.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
20. 20.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. Does bulb 6 glow? (a) Yes (b) No
21. 21.🔺 A 37.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
22. 22.What does a reed switch do? (a) works only while pressed (b) closes when tipped over (c) closes near a magnet (d) springs back when let go
23. 23.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
24. 24.What does a toggle switch do? (a) closes near a magnet (b) springs back when let go (c) flips up or down (d) works only while pressed
25. 25.What does a push button do? (a) flips up or down (b) works only while pressed (c) stays where you flip it (d) closes near a magnet
26. 26.Which drawing is the symbol for a battery? (a) a circle with an X in it (b) a dot where wires meet (c) two or more cell symbols (d) two equal parallel lines
27. 27.🤖 Does a wind-up toy usually have a microcontroller inside? (a) Yes (b) No
28. 28.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
29. 29.⚡ What does a loudspeaker mainly change electricity into? (a) heat (b) sound (c) light (d) movement
30. 30.True or false: a steel coin is an insulator. (a) True (b) False
31. 31.🌐 What does IoT stand for? (a) Input of Tools (b) Internet of Things (c) Internet of Talk (d) Inside of Toys
32. 32.🔍 Which is the odd one out? (a) a table fan (b) an electric kettle (c) an electric drill (d) an exhaust fan
33. 33.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
34. 34.📏 How many amperes (A) is 790 mA? =
35. 35.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
36. 36.True or false: an exhaust fan mainly makes sound. (a) False (b) True
37. 37.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
38. 38.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 2 hours?
39. 39.⏱️ repeat 7 times { buzzer ON; wait 300 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
40. 40.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) quick and clear for all (d) to hide the circuit

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