Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 857 · 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.Which of these mainly gives out light? (a) a traffic signal (b) an electric toy car (c) an electric iron (d) a table fan
2. 2.⚙️ What is an actuator? (a) a program (b) an output that acts (c) a battery (d) a sensor
3. 3.🗺️ Before building a project, what should you write down first? (a) the box colour (b) inputs and outputs (c) nothing at all (d) the final price
4. 4.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets smaller (d) gets bigger
5. 5.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) water carries current (c) it spoils the paint (d) it is just untidy
6. 6.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
7. 7.Which of these is a conductor? (a) a woollen thread (b) a plastic ruler (c) a steel coin (d) a dry cork
8. 8.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 38 °C. What is shown? (a) Cool (b) Warm (c) Hot
9. 9.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 1 glow? (a) Yes (b) No
10. 10.What does a potentiometer do? (a) limits the current (b) senses how hot it is (c) is a resistance knob (d) stores a little charge
11. 11.Which of these is safe? (a) climb an electric pole (b) throw cells in a fire (c) use small battery cells (d) use mains for a project
12. 12.What does the phone app do? (a) acts on a command (b) carries the data (c) measures the real world (d) shows data to you
13. 13.⚠️ Who should be with you when you build a circuit? (a) a trusted adult (b) a stranger online (c) a younger child (d) nobody
14. 14.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) output (b) input (c) process
15. 15.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
16. 16.True or false: a dry cork is an insulator. (a) False (b) True
17. 17.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.True or false: a dot where wires meet is the symbol for a junction. (a) False (b) True
19. 19.Which job needs a pump? (a) show the temperature (b) beep an alarm (c) move water to plants (d) spin a robot’s wheels
20. 20.🔺 A 5 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
21. 21.🔌 Is a steel coin a conductor or an insulator? (a) a conductor (b) an insulator
22. 22.⚡ A device works on 9 V and takes 2 A. What is its power (in watts)? =
23. 23.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
24. 24.🔺 A current of 40 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
26. 26.🔺 A current of 2 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
27. 27.Which of these is measured in amperes (A)? (a) resistance (b) the flow of charge (c) power (d) the push of a cell
28. 28.⏱️ A program says “wait 6250 ms”. How many seconds is that? =
29. 29.🔺 A 0.8 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
30. 30.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
31. 31.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 14000 Ω resistor? (a) yellow-brown-orange (b) brown-yellow-yellow (c) brown-yellow-orange (d) brown-yellow-red
32. 32.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
33. 33.🔁 count = 3
    while (count < 24) { count = count + 3 }
    How many times does the loop run?
34. 34.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
35. 35.Which of these is true of a parallel circuit? (a) own switch for each bulb (b) a break stops every bulb (c) bulbs share the voltage (d) one bulb out, all go out
36. 36.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) quick and clear for all (c) to make it colourful (d) symbols are heavier
37. 37.🔌 Is a plastic ruler a conductor or an insulator? (a) an insulator (b) a conductor
38. 38.⚡ A device works on 3 V and takes 0.25 A. What is its power (in watts)? =
39. 39.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 58 %. What happens? (a) pump OFF (b) pump ON
40. 40.🔺 A current of 40 mA flows when 12 V is joined across a resistor. What is its resistance (in ohms)?

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