Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 29 · 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 current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
2. 2.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
3. 3.True or false: a long and a short line is the symbol for a cell. (a) False (b) True
4. 4.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a small battery pack (c) a mains extension board (d) a wall socket
5. 5.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) battery (b) cell (c) diode (d) wire
6. 6.🔍 Which is the odd one out? (a) a plastic straw (b) a copper wire (c) a glass marble (d) a wooden stick
7. 7.🧩 Which component glows using little power? (a) resistor (b) diode (c) capacitor (d) LED
8. 8.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 70 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
9. 9.⚙️ Which actuator would you use to turn to an exact angle? (a) a pump (b) a servo motor (c) a display (d) a motor
10. 10.🔍 Which is the odd one out? (a) an alert on the phone (b) a temperature reading (c) a soil moisture reading (d) a button press
11. 11.🔺 A current of 25 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🔁 x = 3
    repeat 1 time { x = x × 2 }
    What is x at the end?
13. 13.🔘 When a switch is ON, the circuit is … (a) cut (b) broken (c) open (d) closed
14. 14.🔁 repeat 3 times { repeat 4 times { beep } }
    How many beeps are there?
15. 15.True or false: a straight line is the symbol for a wire. (a) False (b) True
16. 16.True or false: to use old filament bulbs saves electricity. (a) False (b) True
17. 17.True or false: “many values in a range” is a digital signal. (a) True (b) False
18. 18.🌈 In the resistor colour code, which number does white stand for?
19. 19.💡 A battery lights 2 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
20. 20.Which of these is safe? (a) touch a switch when wet (b) throw cells in a fire (c) poke things in a socket (d) stay away from pylons
21. 21.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) prints 1 (d) takes 1 away
22. 22.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 520 Ω resistor? (a) green-red-brown (b) green-red-black (c) green-red-red (d) red-green-brown
23. 23.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 4 of the switches are OFF and the rest are ON. How many bulbs glow?
24. 24.🔍 Which is the odd one out? (a) a plain wall switch (b) a fitness band with app (c) a Wi-Fi weather station (d) a Wi-Fi doorbell camera
25. 25.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) straight lines (d) dotted circles
26. 26.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
27. 27.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 5 % (c) 50 % (d) 0 %
28. 28.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) True (b) False
29. 29.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
30. 30.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
31. 31.True or false: a traffic signal mainly gives out light. (a) False (b) True
32. 32.🔺 A current of 1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🔌 Is a rubber band a conductor or an insulator? (a) a conductor (b) an insulator
34. 34.⚡ A device works on 24 V and takes 1 A. What is its power (in watts)? =
35. 35.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire has come loose (d) all wires are joined
36. 36.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V × I (d) P = V + I
37. 37.🌈 A resistor has the colour bands orange, white, red. What is its value (in ohms)?
38. 38.🔋 Does a bicycle dynamo give electricity or use electricity? (a) gives electricity (b) uses electricity
39. 39.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
40. 40.🔌 Is a copper wire a conductor or an insulator? (a) a conductor (b) an insulator

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