Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 242 · 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 is the odd one out? (a) use mains for a project (b) touch a switch when wet (c) use a cable with cuts (d) take cells out after use
2. 2.Which of these is the process? (a) a motion sensor signal (b) the fan starts (c) decide if soil is dry (d) an alert on the phone
3. 3.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
4. 4.🔋 How many 2 V cells must be joined in series to give 8 V?
5. 5.📏 Voltmeter or ammeter: which one measures current? (a) voltmeter (b) ammeter
6. 6.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) blinks 500 times (d) pauses for half a second
7. 7.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) neither line (c) both lines (d) the shorter line
9. 9.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) Yes (b) No
10. 10.🔺 A current of 20 mA flows when 4.4 V is joined across a resistor. What is its resistance (in ohms)?
11. 11.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
13. 13.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) wait a few seconds (b) switch the pump on/off (c) compare with the limit
14. 14.True or false: a copper wire is a conductor. (a) True (b) False
15. 15.📶 Digital or analog: many values in a range? (a) digital (b) analog
16. 16.🔺 A current of 50 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
17. 17.Which of these is the process? (a) the fan starts (b) a button press (c) a motion sensor signal (d) count button presses
18. 18.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 310 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
19. 19.🔋 What should you do with used-up cells? (a) throw them in a fire (b) give them for recycling (c) cut them open (d) bury them in soil
20. 20.Which of these is safe? (a) throw cells in a fire (b) fly kites in open fields (c) poke things in a socket (d) touch a switch when wet
21. 21.🧭 Which part of a microcontroller board shows the board is on? (a) the pins (b) the power LED (c) the reset button (d) the USB port
22. 22.🔍 An object is 255 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
23. 23.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) none (d) one
24. 24.🔢 To plan an electronics project, which comes first: “test it and fix it” or “pick a problem to solve”? (a) test it and fix it (b) pick a problem to solve
25. 25.📏 In the water-pipe picture of a circuit, voltage is like … (a) the pipe colour (b) the water pressure (c) the water tank lid (d) the tap handle
26. 26.🔘 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 OFF, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) No (b) Yes
27. 27.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
28. 28.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) test it and fix it (b) pick a problem to solve (c) build it with an adult (d) list inputs and outputs
29. 29.True or false: a reed switch closes near a magnet. (a) True (b) False
30. 30.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.Which of these is an IoT device? (a) a battery torch (b) a paper calendar (c) a wind-up clock (d) a Wi-Fi smart plug
32. 32.🔍 Which is the odd one out? (a) iron one shirt at a time (b) run fans in empty rooms (c) leave the TV on standby (d) set the AC to 24 °C
33. 33.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “read the soil sensor”? (a) switch the pump on/off (b) read the soil sensor
34. 34.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
35. 35.What does a slide switch do? (a) works only while pressed (b) slides side to side (c) closes when tipped over (d) stays where you flip it
36. 36.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 650 ms }
    How many milliseconds does one blink (ON + OFF) take?
37. 37.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) tell it your passwords (b) mute it when not in use (c) put it in the bathroom (d) let strangers use it
38. 38.🌐 A weather station sends one reading every 30 seconds. How many readings does it send in 7 minutes?
39. 39.Which of these saves electricity? (a) use daylight to read (b) use old filament bulbs (c) iron one shirt at a time (d) leave fridge door open
40. 40.🔍 A distance sensor sends a sound pulse and hears the echo 1 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?

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