Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 918 · 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.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
2. 2.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) an LED (d) a motor
3. 3.🤖 if (sound > 80) { red LED ON } else { green LED ON }
   The sound sensor reads 69. What happens? (a) red LED ON (b) green LED ON
4. 4.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when either is ON (c) when both are OFF (d) when both are ON
5. 5.🔁 total = 0
   for i = 1 to 3 { total = total + i }
   What is total at the end?
6. 6.⏱️ loop forever { LED ON; wait 450 ms; LED OFF; wait 750 ms }
   How many milliseconds does one blink (ON + OFF) take?
7. 7.💡 5 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
8. 8.Which of these is a conductor? (a) a paper strip (b) a rubber eraser (c) a metal paper clip (d) a rubber band
9. 9.True or false: a laptop runs one small program. (a) True (b) False
10. 10.Which of these usually has a microcontroller inside? (a) a hand pump (b) a bicycle bell (c) a spinning top (d) a digital thermometer
11. 11.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a cotton thread across the gap. Does the bulb glow? (a) Yes (b) No
12. 12.🔺 A current of 2.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) input (b) output (c) process
14. 14.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) it starts again (c) the board breaks (d) it stops forever
15. 15.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) process (b) output (c) input
16. 16.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V + R (d) I = V ÷ R
17. 17.🔍 An object is 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
18. 18.🔢 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
19. 19.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one for each bulb (d) one
20. 20.🔍 Which is the odd one out? (a) share the Wi-Fi key (b) ignore update messages (c) set a strong password (d) post your live location
21. 21.True or false: “own switch for each bulb” is true of a series circuit. (a) True (b) False
22. 22.Which job needs a sound sensor? (a) start a fan when hot (b) switch on lamps at dusk (c) spot someone walking in (d) switch on with a clap
23. 23.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
24. 24.🔋 How many volts does one ordinary torch cell give? (a) 230 V (b) 1.5 V (c) 15 V (d) 0.5 V
25. 25.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a wall socket (c) a mains extension board (d) a small battery pack
26. 26.📶 A pin that reads a push button is set as … (a) an input (b) an output (c) a resistor (d) a battery
27. 27.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
28. 28.⏱️ How many milliseconds is a wait of 0.8 seconds?
29. 29.True or false: an LED lamp mainly gives out heat. (a) False (b) True
30. 30.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
31. 31.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
32. 32.Which of these is safe? (a) use small battery cells (b) poke things in a socket (c) use a cable with cuts (d) fly a kite near wires
33. 33.🔌 Is a light sensor an input or an output for a microcontroller? (a) input (b) output
34. 34.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 25 °C. What happens? (a) fan ON (b) fan OFF
35. 35.🗺️ Before building a project, what should you write down first? (a) the final price (b) nothing at all (c) inputs and outputs (d) the box colour
36. 36.Which job is done by the pins? (a) restarts the program (b) connect sensors and LEDs (c) brings power and code (d) shows the board is on
37. 37.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity
38. 38.🌈 In the resistor colour code, which number does grey stand for?
39. 39.🔐 Is it a good or a risky habit to post your live location? (a) good habit (b) risky habit
40. 40.Which of these uses electricity? (a) a battery (b) a washing machine (c) a wind turbine (d) a cell

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