Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 47 · 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.🔁 x = 3
   repeat 3 times { x = x × 2 }
   What is x at the end?
2. 2.True or false: to stay away from pylons is not safe. (a) True (b) False
3. 3.🔦 A circuit has a new cell, a bulb with a broken filament 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) No (b) Yes
4. 4.Which of these mainly makes sound? (a) a street light (b) a toaster (c) a room heater (d) a buzzer
5. 5.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) neither line (c) both lines (d) the longer line
6. 6.True or false: a street light mainly gives out light. (a) False (b) True
7. 7.Which drawing is the symbol for a voltmeter? (a) a plain rectangle (b) a small empty box (c) triangle, bar and arrows (d) a circle with V inside
8. 8.Which of these is the input? (a) an LED lights up (b) a temperature reading (c) check if temp > 30 (d) a buzzer beeps
9. 9.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
10. 10.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 2 minutes?
11. 11.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
12. 12.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
13. 13.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
14. 14.🔋 How many 1.2 V cells must be joined in series to give 4.8 V?
15. 15.What does an LDR do? (a) makes a beeping sound (b) senses how hot it is (c) glows using little power (d) senses how bright it is
16. 16.Which of these is true of a series circuit? (a) one out, the rest glow (b) each gets the full volts (c) one bulb out, all go out (d) many paths for current
17. 17.🗺️ Before building a project, what should you write down first? (a) the box colour (b) nothing at all (c) the final price (d) inputs and outputs
18. 18.Which of these is a conductor? (a) a paper strip (b) a woollen thread (c) a plastic straw (d) an iron nail
19. 19.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) an open circuit (b) a short circuit (c) a parallel circuit (d) a safe circuit
20. 20.True or false: a circle with A inside is the symbol for an ammeter. (a) False (b) True
21. 21.🔍 Which sensor would you use to stop a robot near walls? (a) a light sensor (b) a motion sensor (c) a distance sensor (d) a temperature sensor
22. 22.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they get dimmer (c) they keep glowing (d) they all go out
23. 23.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
24. 24.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.🧩 Which component blows if current is high? (a) diode (b) capacitor (c) fuse (d) LED
26. 26.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) the bulb is unscrewed (d) a cell is taken out
27. 27.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) none (c) one (d) two
28. 28.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
29. 29.🔋 6 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
30. 30.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) each gets full voltage (d) so all go off together
31. 31.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) stay the same (d) zero
32. 32.Which of these is measured in amperes (A)? (a) resistance (b) current (c) voltage (d) how much a part resists
33. 33.Which job needs a rain sensor? (a) close a window in rain (b) water a dry plant (c) switch on lamps at dusk (d) stop a robot near walls
34. 34.True or false: to switch on with a clap, use a temperature sensor. (a) False (b) True
35. 35.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
36. 36.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 590 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
37. 37.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) light energy (b) sound energy (c) movement energy (d) chemical energy
39. 39.⚠️ Who should be with you when you build a circuit? (a) a trusted adult (b) a younger child (c) nobody (d) a stranger online
40. 40.🔦 A circuit has a used-up (dead) 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 dry cork. Does the bulb glow? (a) No (b) Yes

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