Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 408 · 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.⚠️ Is it safe to fly kites in open fields? (a) not safe (b) safe
2. 2.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
3. 3.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
   The temperature is 34 °C. What is shown? (a) Cool (b) Warm (c) Hot
4. 4.Which of these is measured in volts (V)? (a) the flow of charge (b) voltage (c) power (d) current
5. 5.What does a resistor do? (a) blows if current is high (b) beeps for an alarm (c) is a resistance knob (d) limits the current
6. 6.🔋 Cells joined + to − in a row (series) give … (a) a smaller voltage (b) a bigger voltage (c) no voltage (d) the same voltage
7. 7.What does a potentiometer do? (a) beeps for an alarm (b) is a resistance knob (c) has coloured bands (d) lets current go one way
8. 8.📏 How many ohms (Ω) is 0.4 kΩ?
9. 9.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
10. 10.🔘 Which kind of switch stays where you flip it? (a) a push button (b) a slide switch (c) a reed switch (d) a toggle switch
11. 11.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
12. 12.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) cell (b) bulb (c) wire (d) junction
13. 13.Which of these wastes electricity? (a) close the fridge quickly (b) unplug idle chargers (c) leave the TV on standby (d) set the AC to 24 °C
14. 14.True or false: a circle with A inside is the symbol for an ammeter. (a) False (b) True
15. 15.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
17. 17.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 48 %. What happens? (a) pump ON (b) pump OFF
18. 18.🔺 A 0.6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
19. 19.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
20. 20.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
21. 21.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
22. 22.True or false: a steel coin is an insulator. (a) True (b) False
23. 23.🔋 Does a wind turbine give electricity or use electricity? (a) gives electricity (b) uses electricity
24. 24.💡 2 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
25. 25.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
26. 26.🤖 Does a smart watch usually have a microcontroller inside? (a) Yes (b) No
27. 27.True or false: to tap unknown app links is a risky habit. (a) True (b) False
28. 28.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 570 Ω resistor? (a) green-violet-brown (b) green-violet-black (c) green-violet-red (d) violet-green-brown
29. 29.True or false: a line lifted at a gap is the symbol for a wire. (a) True (b) False
30. 30.🧮 Resistors of 150 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
31. 31.🔁 repeat 4 times { repeat 6 times { beep } }
    How many beeps are there?
32. 32.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
33. 33.🌈 A resistor has the colour bands orange, blue, orange. What is its value (in ohms)?
34. 34.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 1 second?
35. 35.Which of these is a risky habit? (a) keep factory passwords (b) log out of shared phones (c) share only needed data (d) read app permissions
36. 36.Which of these is an insulator? (a) a rubber band (b) a brass key (c) aluminium foil (d) a safety pin
37. 37.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) inputs and outputs (c) the box colour (d) the final price
38. 38.🔺 A current of 10 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
39. 39.🔍 Which is the odd one out? (a) a glass marble (b) an iron nail (c) a cotton thread (d) a rubber band
40. 40.True or false: “how loud a sound is” is a digital signal. (a) False (b) True

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