Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 16 · 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.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
2. 2.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
3. 3.🌈 A resistor has the colour bands blue, white, orange. What is its value in kilo-ohms (kΩ)? =
4. 4.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
5. 5.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) volt (V) (c) ampere (A) (d) watt (W)
6. 6.⚙️ Which actuator would you use to turn to an exact angle? (a) a display (b) a motor (c) an LED (d) a servo motor
7. 7.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
   The temperature is 31 °C. What is shown? (a) Warm (b) Cool (c) Hot
8. 8.🧩 Which component limits the current? (a) potentiometer (b) buzzer (c) diode (d) resistor
9. 9.⚡ A device works on 1.5 V and takes 1 A. What is its power (in watts)? =
10. 10.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
11. 11.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a slide switch (c) a toggle switch (d) a push button
12. 12.True or false: to install software updates is a risky habit. (a) False (b) True
13. 13.🔍 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
14. 14.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) the shorter line (c) neither line (d) both lines
15. 15.🔍 Which is the odd one out? (a) a paper strip (b) a wooden stick (c) a rubber eraser (d) a safety pin
16. 16.🔐 Which is the strongest password for a home smart camera? (a) admin (b) password (c) Tiger#Lamp42!Moon (d) 123456
17. 17.True or false: to stop if a part gets hot is not safe. (a) True (b) False
18. 18.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
19. 19.Which drawing is the symbol for a motor? (a) a plain rectangle (b) triangle, bar and arrows (c) a circle with M inside (d) a circle with V inside
20. 20.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) share it with friends (c) post it online (d) ask a parent first
21. 21.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) the cloud stores it (b) the app shows it (c) the board reads it (d) it is sent by Wi-Fi
22. 22.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) one bulb out, all go out (c) each gets the full volts (d) a break stops every bulb
23. 23.🔍 Which is the odd one out? (a) a buzzer (b) a water heater (c) a school bell (d) a doorbell
24. 24.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
25. 25.⚡ What does a loudspeaker mainly change electricity into? (a) light (b) sound (c) heat (d) movement
26. 26.Which of these usually has a microcontroller inside? (a) a bicycle bell (b) a digital thermometer (c) a wind-up toy (d) a spinning top
27. 27.📏 How many kilowatts (kW) is 2400 W? =
28. 28.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel
29. 29.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
30. 30.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
31. 31.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “build it with an adult”? (a) pick a problem to solve (b) build it with an adult
32. 32.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 60 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
33. 33.Which of these wastes electricity? (a) use daylight to read (b) iron one shirt at a time (c) close the fridge quickly (d) set the AC to 24 °C
34. 34.Which of these is measured in volts (V)? (a) how much a part resists (b) the flow of charge (c) voltage (d) energy used each second
35. 35.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 500 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
36. 36.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire has come loose (d) the bulb is unscrewed
37. 37.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I × R (d) V = I + R
38. 38.🔢 To get a sensor reading onto a phone, which comes first: “the cloud stores it” or “the sensor measures”? (a) the sensor measures (b) the cloud stores it
39. 39.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
40. 40.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a capacitor (c) a buzzer (d) a diode

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