Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 709 · 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 must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
2. 2.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
3. 3.🔺 A current of 3 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
4. 4.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
5. 5.True or false: a rubber band is a conductor. (a) False (b) True
6. 6.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
7. 7.🤖 Does a candle usually have a microcontroller inside? (a) No (b) Yes
8. 8.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
9. 9.Which of these is an input? (a) a motion sensor (b) a buzzer (c) a servo motor (d) a small display
10. 10.🔺 A current of 50 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
11. 11.True or false: a microcontroller runs many apps at once. (a) False (b) True
12. 12.⚡ A 3 W device works on 3 V. What current does it take (in amperes)? =
13. 13.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) quick and clear for all (d) symbols are heavier
14. 14.🌈 A resistor has the colour bands grey, blue, red. What is its value (in ohms)?
15. 15.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) Yes (b) No
16. 16.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
17. 17.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) neither line (c) the shorter line (d) both lines
18. 18.🔘 Which kind of switch flips up or down? (a) a push button (b) a toggle switch (c) a reed switch (d) a tilt switch
19. 19.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
20. 20.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
21. 21.True or false: a cotton thread is an insulator. (a) True (b) False
22. 22.⚡ What does a siren mainly change electricity into? (a) movement (b) heat (c) sound (d) light
23. 23.🌐 A soil sensor sends a reading to an app every 10 minutes. How many readings arrive in 2 hours?
24. 24.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) waits 500 seconds (d) pauses for half a second
25. 25.Which of these is an input? (a) a buzzer (b) an LED (c) a temperature sensor (d) a small display
26. 26.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
27. 27.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 36 °C. What is shown? (a) Warm (b) Hot (c) Cool
28. 28.⏱️ How many milliseconds is a wait of 4.4 seconds?
29. 29.⚠️ Is it safe to dry your hands first? (a) not safe (b) safe
30. 30.🔺 A 10 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
31. 31.📏 Which unit measures voltage? (a) watt (W) (b) ampere (A) (c) volt (V) (d) ohm (Ω)
32. 32.🤖 What is a microcontroller? (a) a computer on one chip (b) a kind of bulb (c) a type of battery (d) a big desktop computer
33. 33.🔺 A current of 0.2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🔍 Which is the odd one out? (a) use mains for a project (b) throw cells in a fire (c) keep drinks far away (d) climb an electric pole
35. 35.🧮 Resistors of 10 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
36. 36.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
37. 37.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
38. 38.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
39. 39.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
40. 40.True or false: “a button: pressed or not” is an analog signal. (a) False (b) True

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