Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 819 · 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.True or false: “the room temperature” is an analog signal. (a) True (b) False
2. 2.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
3. 3.💡 5 identical bulbs are in parallel and each one takes 0.5 A. What total current (in amperes) comes from the battery? =
4. 4.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
   The temperature is 28 °C. What is shown? (a) Hot (b) Cool (c) Warm
5. 5.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) straight lines (d) dotted circles
6. 6.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
7. 7.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 300 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
8. 8.Which of these is measured in amperes (A)? (a) energy used each second (b) the push of a cell (c) resistance (d) current
9. 9.Which job is done by the reset button? (a) connect sensors and LEDs (b) runs the program (c) keeps the voltage steady (d) restarts the program
10. 10.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
11. 11.💡 6 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. Does bulb 5 glow? (a) No (b) Yes
12. 12.True or false: “many paths for current” is true of a series circuit. (a) True (b) False
13. 13.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) light energy (b) chemical energy (c) movement energy (d) sound energy
14. 14.🔍 Which is the odd one out? (a) compare with a limit (b) a soil moisture reading (c) a button press (d) a motion sensor signal
15. 15.🔍 Which is the odd one out? (a) a buzzer beeps (b) an alert on the phone (c) count button presses (d) the pump turns on
16. 16.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 2 hours?
17. 17.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “it is sent by Wi-Fi”? (a) it is sent by Wi-Fi (b) the sensor measures
18. 18.🌈 A resistor has the colour bands orange, red, yellow. What is its value in kilo-ohms (kΩ)? =
19. 19.⏱️ A program says “wait 9250 ms”. How many seconds is that? =
20. 20.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) input (b) output
21. 21.🔺 A current of 0.25 A flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
22. 22.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire is cut (d) the loop is complete
23. 23.🔁 x = 2
    repeat 2 times { x = x × 2 }
    What is x at the end?
24. 24.🔍 Which is the odd one out? (a) a brass key (b) a dry cork (c) aluminium foil (d) a metal paper clip
25. 25.🔌 Is a light sensor an input or an output for a microcontroller? (a) output (b) input
26. 26.🌈 A resistor has the colour bands yellow, black, red. What is its value (in ohms)?
27. 27.🧮 A 10 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
28. 28.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 10 seconds?
29. 29.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) LED (b) motor (c) ammeter (d) cell
30. 30.🌈 A resistor has the colour bands violet, black, yellow. What is its value in kilo-ohms (kΩ)? =
31. 31.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
32. 32.What does a potentiometer do? (a) lets current go one way (b) makes a beeping sound (c) blows if current is high (d) is a resistance knob
33. 33.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
34. 34.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the filament (d) the switch
35. 35.💡 2 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
36. 36.🔋 Does a cell give electricity or use electricity? (a) uses electricity (b) gives electricity
37. 37.💡 4 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 3 is taken out of its holder. How many bulbs glow?
38. 38.🔺 A current of 50 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
39. 39.💡 An LED is joined to a 6 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) does not light (b) lights up (c) may burn out
40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open

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