Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 469 · 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 red LED (it uses 2 V) is joined with a 200 Ω resistor to a 4 V supply. What current flows (in mA)?
2. 2.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
   The distance sensor reads 36 cm. What happens? (a) buzzer is silent (b) buzzer beeps
3. 3.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 320 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
4. 4.Which of these is a conductor? (a) a plastic straw (b) a woollen thread (c) a graphite rod (d) a rubber band
5. 5.🔌 Is a steel spoon a conductor or an insulator? (a) a conductor (b) an insulator
6. 6.Which of these is not safe? (a) take cells out after use (b) fly kites in open fields (c) touch a switch when wet (d) stay away from pylons
7. 7.🔘 Which kind of switch closes near a magnet? (a) a slide switch (b) a tilt switch (c) a reed switch (d) a push button
8. 8.🤖 Does a wind-up toy usually have a microcontroller inside? (a) Yes (b) No
9. 9.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
10. 10.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I
11. 11.⏱️ A program says “wait 8500 ms”. How many seconds is that? =
12. 12.🧩 Which component makes a beeping sound? (a) resistor (b) potentiometer (c) buzzer (d) LDR
13. 13.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
14. 14.📶 On a 5 V board, a pin set HIGH gives about … (a) 0 V (b) 50 V (c) 230 V (d) 5 V
15. 15.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) gets smaller (c) becomes zero (d) stays the same
16. 16.🔋 Does a battery give electricity or use electricity? (a) gives electricity (b) uses electricity
17. 17.🔍 Which is the odd one out? (a) an electric toy car (b) a torch (c) a street light (d) an LED lamp
18. 18.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) their sum (c) always zero (d) less than either one
19. 19.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
20. 20.📏 How many amperes (A) is 2240 mA? =
21. 21.🔌 Is a wooden stick a conductor or an insulator? (a) a conductor (b) an insulator
22. 22.Which drawing is the symbol for a battery? (a) a circle with an X in it (b) a dot where wires meet (c) two equal parallel lines (d) many long-short pairs
23. 23.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 10 (c) 1000 (d) 100
24. 24.🔋 How many 2 V cells must be joined in series to give 12 V?
25. 25.True or false: triangle against a bar is the symbol for a switch. (a) False (b) True
26. 26.True or false: to close a window in rain, use a distance sensor. (a) False (b) True
27. 27.💡 2 identical bulbs are joined in series with a 6 V battery (ideal wires). How many volts does each bulb get? =
28. 28.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 120 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
29. 29.🔺 A current of 0.2 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
30. 30.🧩 Which component has coloured bands? (a) potentiometer (b) fuse (c) resistor (d) transistor
31. 31.🔘 Which kind of switch closes when tipped over? (a) a toggle switch (b) a reed switch (c) a push button (d) a tilt switch
32. 32.🌈 In the resistor colour code, which number does green stand for?
33. 33.Which of these is measured in watts (W)? (a) energy used each second (b) the flow of charge (c) the push of a cell (d) how much a part resists
34. 34.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 14 °C. What is shown? (a) Hot (b) Cool (c) Warm
35. 35.💡 4 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
36. 36.Which of these mainly makes sound? (a) a rice cooker (b) a street light (c) a siren (d) a table fan
37. 37.True or false: to use mains for a project is safe. (a) False (b) True
38. 38.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a cell is taken out
39. 39.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a Wi-Fi weather station (c) a battery torch (d) an app-controlled bulb
40. 40.🔍 Which is the odd one out? (a) open a phone charger (b) touch a switch when wet (c) use small battery cells (d) touch a fallen wire

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