Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 18 · 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.🔺 A 10 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
2. 2.🔁 total = 0
   for i = 1 to 7 { total = total + i }
   What is total at the end?
3. 3.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
4. 4.Which of these is not safe? (a) stop if a part gets hot (b) take cells out after use (c) use a cable with cuts (d) fly kites in open fields
5. 5.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
6. 6.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
7. 7.Which drawing is the symbol for a capacitor? (a) a line lifted at a gap (b) a circle with M inside (c) two equal parallel lines (d) one tall, one short bar
8. 8.🔌 Is a wooden stick a conductor or an insulator? (a) a conductor (b) an insulator
9. 9.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) neither part (d) the else part
10. 10.🔢 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
11. 11.💡 3 identical bulbs are joined in parallel across a 9 V battery (ideal wires). How many volts does each bulb get? =
12. 12.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) a power source (d) an output
13. 13.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they get dimmer (c) they explode (d) they keep glowing
14. 14.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is ON and D is ON. Does the bulb glow? (a) No (b) Yes
15. 15.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V + I (d) P = V ÷ I
16. 16.What does an LDR do? (a) blows if current is high (b) boosts a small signal (c) is a resistance knob (d) senses how bright it is
17. 17.🔌 Most metals are good … (a) batteries (b) conductors (c) magnets only (d) insulators
18. 18.Which of these mainly makes sound? (a) an LED lamp (b) a rice cooker (c) a traffic signal (d) a buzzer
19. 19.True or false: to keep drinks far away is safe. (a) False (b) True
20. 20.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second
22. 22.True or false: to keep an incubator warm, use a temperature sensor. (a) False (b) True
23. 23.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
24. 24.🔍 Which is the odd one out? (a) throw cells in a fire (b) fly a kite near wires (c) open a phone charger (d) use small battery cells
25. 25.🔺 A current of 3 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 66. What happens? (a) green LED ON (b) red LED ON
27. 27.⏱️ How many milliseconds is a wait of 1.3 seconds?
28. 28.🔺 A 2 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
29. 29.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
30. 30.Which of these mainly gives out heat? (a) a school bell (b) a traffic signal (c) an electric kettle (d) a loudspeaker
31. 31.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
32. 32.🧮 A 150 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
33. 33.🔐 Is it a good or a risky habit to log out of shared phones? (a) good habit (b) risky habit
34. 34.📏 How many milliamperes (mA) is 2.99 A?
35. 35.True or false: a reed switch slides side to side. (a) True (b) False
36. 36.🔺 A current of 2.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 84 Ω resistor? (a) yellow-grey-black (b) grey-yellow-black (c) white-yellow-black (d) grey-yellow-brown
38. 38.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
39. 39.True or false: a resistor limits the current. (a) False (b) True
40. 40.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)

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