Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 550 · 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 of these is the input? (a) an LED lights up (b) the pump turns on (c) decide if soil is dry (d) a motion sensor signal
2. 2.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) input (b) output (c) process
3. 3.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) not joined (d) by Wi-Fi
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 61 Ω resistor? (a) blue-brown-brown (b) violet-brown-black (c) brown-blue-black (d) blue-brown-black
5. 5.⚙️ What is an actuator? (a) a sensor (b) an output that acts (c) a battery (d) a program
6. 6.🔌 Most metals are good … (a) magnets only (b) conductors (c) insulators (d) batteries
7. 7.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
8. 8.True or false: two equal parallel lines is the symbol for a battery. (a) False (b) True
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
10. 10.💡 What does LED stand for? (a) low energy device (b) large electric dial (c) light energy dial (d) light-emitting diode
11. 11.🔺 A current of 0.2 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.What does a fuse do? (a) makes things spin (b) senses how bright it is (c) blows if current is high (d) turns a fan or wheels
13. 13.💡 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
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
14. 14.🔺 A current of 0.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7300 Ω resistor? (a) violet-orange-orange (b) orange-violet-red (c) violet-orange-red (d) violet-orange-brown
16. 16.⏱️ How many milliseconds is a wait of 0.2 seconds?
17. 17.🔍 Which is the odd one out? (a) a push button (b) a speaker (c) a motion sensor (d) a temperature sensor
18. 18.⚡ What do we call a flow of electric charge through a wire? (a) electric current (b) a magnet (c) sound (d) friction
19. 19.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 36 °C. What is shown? (a) Cool (b) Warm (c) Hot
20. 20.🔢 To plan an electronics project, which comes first: “draw the circuit diagram” or “list inputs and outputs”? (a) draw the circuit diagram (b) list inputs and outputs
21. 21.🔺 A 2 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
22. 22.🌐 Is a pencil sharpener an IoT device? (a) an IoT device (b) not an IoT device
23. 23.Which of these usually has a microcontroller inside? (a) a plain wall switch (b) a candle (c) a hand pump (d) a digital thermometer
24. 24.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 200 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
25. 25.True or false: to set up with a parent is a risky habit. (a) True (b) False
26. 26.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) bulbs share the voltage (d) many paths for current
27. 27.True or false: a loudspeaker mainly makes sound. (a) True (b) False
28. 28.💡 An LED is joined to a 5 V battery through a 470 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) may burn out (c) lights up
29. 29.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
30. 30.⚡ A 0.6 W device works on 6 V. What current does it take (in amperes)? =
31. 31.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
32. 32.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
33. 33.🌈 A resistor has the colour bands yellow, orange, orange. What is its value (in ohms)?
34. 34.🌐 A weather station sends one reading every 30 seconds. How many readings does it send in 10 minutes?
35. 35.True or false: a toggle switch stays where you flip it. (a) False (b) True
36. 36.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.Which of these is a risky habit? (a) accept every permission (b) change default passwords (c) read app permissions (d) turn off unused gadgets
38. 38.🔌 Which metal is used for most electric wires at home? (a) plastic (b) rubber (c) copper (d) glass
39. 39.💡 Why does an LED need a resistor in series? (a) to store charge (b) to make it brighter (c) to change its colour (d) to limit the current
40. 40.🔺 A current of 0.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =

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