Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 194 · 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 3 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
2. 2.Which drawing is the symbol for a resistor? (a) a plain rectangle (b) a straight line (c) a long and a short line (d) triangle, bar and arrows
3. 3.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 0.5 V (c) 1.5 V (d) 230 V
4. 4.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
5. 5.🔢 To plan an electronics project, what comes right after “build it with an adult”? (a) draw the circuit diagram (b) list inputs and outputs (c) test it and fix it (d) pick a problem to solve
6. 6.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 260 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
7. 7.Which of these is safe? (a) touch a switch when wet (b) build with an adult near (c) use a cable with cuts (d) use mains for a project
8. 8.🤖 if (light < 500) { lamp ON } else { lamp OFF }
   The light sensor reads 628. What happens? (a) lamp OFF (b) lamp ON
9. 9.Which of these is true of a series circuit? (a) each gets the full volts (b) used in house wiring (c) one out, the rest glow (d) bulbs share the voltage
10. 10.💡 2 identical bulbs are joined in parallel across a 3 V battery (ideal wires). How many volts does each bulb get? =
11. 11.⚡ Which tiny particles drift along a metal wire to carry the current? (a) water drops (b) dust particles (c) electrons (d) photons
12. 12.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = I ÷ V (d) P = V + I
13. 13.⚡ A device works on 12 V and takes 0.5 A. What is its power (in watts)? =
14. 14.True or false: to stay away from pylons is safe. (a) True (b) False
15. 15.Which job needs a temperature sensor? (a) open blinds at sunrise (b) keep an incubator warm (c) make a parking alarm (d) water a dry plant
16. 16.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
17. 17.🔺 A 2 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
18. 18.Which of these mainly makes movement? (a) a mixer grinder (b) a siren (c) a toaster (d) an LED lamp
19. 19.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they get dimmer (c) they keep glowing (d) they explode
20. 20.True or false: voltage is measured in volts (V). (a) True (b) False
21. 21.🔋 How many 1.5 V cells must be joined in series to give 10.5 V?
22. 22.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False
23. 23.🌈 A resistor has the colour bands blue, red, red. What is its value in kilo-ohms (kΩ)? =
24. 24.🔌 Is a water pump an input or an output for a microcontroller? (a) output (b) input
25. 25.🔍 Which is the odd one out? (a) poke things in a socket (b) take cells out after use (c) dry your hands first (d) stop if a part gets hot
26. 26.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a smart energy meter (c) a Wi-Fi doorbell camera (d) a plain table fan
27. 27.🔋 What is a battery? (a) one single wire (b) a kind of bulb (c) two or more cells joined (d) a switch with a lid
28. 28.🗺️ Before building a project, what should you write down first? (a) the final price (b) the box colour (c) inputs and outputs (d) nothing at all
29. 29.What does a push button do? (a) closes when tipped over (b) works only while pressed (c) stays where you flip it (d) flips up or down
30. 30.🔺 A current of 1.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
31. 31.⚡ A 0.75 W device works on 1.5 V. What current does it take (in amperes)? =
32. 32.🔋 3 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
33. 33.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the board reads it (b) the app shows it (c) the sensor measures (d) the cloud stores it
34. 34.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) process (b) output (c) input
35. 35.⚡ A 0.6 W device works on 3 V. What current does it take (in amperes)? =
36. 36.⚡ A device works on 12 V and takes 1 A. What is its power (in watts)? =
37. 37.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
38. 38.🧮 Four equal 400 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.⚠️ Is it safe to use small battery cells? (a) not safe (b) safe
40. 40.Which of these is an insulator? (a) an iron nail (b) a safety pin (c) a dry cork (d) aluminium foil

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