Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 502 · 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 smart speaker is always listening for its wake word. What is a sensible habit? (a) put it in the bathroom (b) let strangers use it (c) tell it your passwords (d) mute it when not in use
2. 2.⏱️ A program says “wait 500 ms”. How many seconds is that? =
3. 3.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
4. 4.🤖 What is a microcontroller? (a) a kind of bulb (b) a type of battery (c) a big desktop computer (d) a computer on one chip
5. 5.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
6. 6.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
   The temperature is 34 °C. What is shown? (a) Hot (b) Cool (c) Warm
7. 7.📶 Digital or analog: a button: pressed or not? (a) digital (b) analog
8. 8.🧮 Resistors of 22 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.🔌 Is an iron nail a conductor or an insulator? (a) an insulator (b) a conductor
10. 10.🧮 A 1.6 V battery is joined to 2 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
11. 11.🔐 Is it a good or a risky habit to set up with a parent? (a) risky habit (b) good habit
12. 12.Which of these is not safe? (a) build with an adult near (b) stay away from pylons (c) touch a fallen wire (d) use small battery cells
13. 13.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 count = 0
    while (count < 6) { count = count + 3 }
    How many times does the loop run?
15. 15.True or false: to change default passwords is a good habit. (a) False (b) True
16. 16.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = I ÷ V (d) R = V + I
17. 17.🔺 A current of 40 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
18. 18.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a wire has come loose (d) the loop is complete
20. 20.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 1000 ms }
    How many milliseconds does one blink (ON + OFF) take?
21. 21.What does an LDR do? (a) blows if current is high (b) boosts a small signal (c) senses how bright it is (d) limits the current
22. 22.Which of these is a good habit? (a) share the Wi-Fi key (b) accept every permission (c) change default passwords (d) post your live location
23. 23.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is ON, C is OFF and D is OFF. Does the bulb glow? (a) No (b) Yes
24. 24.Which of these uses electricity? (a) a generator (b) a solar panel (c) a power station (d) a computer
25. 25.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 250 ms }
    How many milliseconds does one blink (ON + OFF) take?
26. 26.🌈 A resistor has the colour bands violet, orange, orange. What is its value in kilo-ohms (kΩ)? =
27. 27.Which job needs a sound sensor? (a) switch on lamps at dusk (b) switch on with a clap (c) open blinds at sunrise (d) keep an incubator warm
28. 28.True or false: a ceiling fan mainly makes movement. (a) False (b) True
29. 29.🧮 Resistors of 47 Ω, 50 Ω, 10 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
30. 30.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
31. 31.🤖 Does a candle usually have a microcontroller inside? (a) Yes (b) No
32. 32.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 2 glow? (a) Yes (b) No
33. 33.💡 5 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
34. 34.Which of these is true of a series circuit? (a) own switch for each bulb (b) one out, the rest glow (c) many paths for current (d) a single current path
35. 35.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 270 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
36. 36.Which of these mainly makes movement? (a) a traffic signal (b) a toaster (c) an electric toy car (d) a night lamp
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 43000 Ω resistor? (a) yellow-orange-yellow (b) orange-yellow-orange (c) yellow-orange-red (d) yellow-orange-orange
38. 38.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 watt
39. 39.⚡ A 13.5 W device works on 9 V. What current does it take (in amperes)? =
40. 40.⚙️ What is an actuator? (a) a program (b) a battery (c) an output that acts (d) a sensor

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