Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 820 · 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 resistor do? (a) lets current go one way (b) beeps for an alarm (c) is a resistance knob (d) has coloured bands
2. 2.📏 How many amperes (A) is 1190 mA? =
3. 3.💡 5 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
4. 4.🔁 total = 0
   for i = 1 to 10 { total = total + i }
   What is total at the end?
5. 5.📏 How many watts (W) is 0.1 kW?
6. 6.⚡ Which formula gives electric power? (a) P = V + I (b) P = I ÷ V (c) P = V × I (d) P = V ÷ I
7. 7.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
8. 8.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
9. 9.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) smaller (d) stay the same
10. 10.⚡ Which tiny particles drift along a metal wire to carry the current? (a) dust particles (b) photons (c) water drops (d) electrons
11. 11.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
12. 12.Which of these is true of a parallel circuit? (a) many paths for current (b) a break stops every bulb (c) one bulb out, all go out (d) a single current path
13. 13.True or false: a plastic straw is a conductor. (a) True (b) False
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) Yes (b) No
15. 15.🌈 In the resistor colour code, which number does green stand for?
16. 16.Which of these is a conductor? (a) a rubber band (b) aluminium foil (c) a glass marble (d) a dry cork
17. 17.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 20 readings take?
18. 18.🔐 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
19. 19.True or false: “a door: open or shut” is an analog signal. (a) False (b) True
20. 20.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) to hide the circuit (d) quick and clear for all
21. 21.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) both parts (d) the else part
22. 22.🔍 Which is the odd one out? (a) a dry cork (b) a wooden stick (c) a woollen thread (d) a metal paper clip
23. 23.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 444. What happens? (a) lamp OFF (b) lamp ON
24. 24.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel
25. 25.🧮 Resistors of 330 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
26. 26.🔺 A 20 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
27. 27.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
28. 28.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
29. 29.🔺 A current of 1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
30. 30.Which of these is the input? (a) count button presses (b) a light level reading (c) check if temp > 30 (d) the fan starts
31. 31.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) pauses for half a second (d) waits 500 seconds
32. 32.True or false: a cotton thread is an insulator. (a) False (b) True
33. 33.⚡ A device works on 6 V and takes 0.5 A. What is its power (in watts)? =
34. 34.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) double the voltage (c) no voltage (d) half the voltage
35. 35.🧩 A capacitor in a circuit can … (a) spin a wheel (b) make light (c) measure heat (d) store charge briefly
36. 36.🔋 8 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
37. 37.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 120 readings take?
38. 38.🔍 Which sensor would you use to close a window in rain? (a) a distance sensor (b) a rain sensor (c) a gas sensor (d) a motion sensor
39. 39.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 28 %. What happens? (a) pump ON (b) pump OFF
40. 40.⚡ What does an electric drill mainly change electricity into? (a) heat (b) light (c) sound (d) movement

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