Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 625 · 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 colour bands (1st digit, 2nd digit, multiplier) mark an 82000 Ω resistor? (a) grey-red-yellow (b) grey-red-orange (c) grey-red-red (d) red-grey-orange
2. 2.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
3. 3.True or false: “a motion sensor signal” is the input. (a) True (b) False
4. 4.🔍 Which is the odd one out? (a) a glass marble (b) a plastic ruler (c) a plastic straw (d) a brass key
5. 5.Which job needs a display? (a) open a gate to 90° (b) move water to plants (c) beep an alarm (d) show the temperature
6. 6.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
7. 7.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 950 ms }
   How many milliseconds does one blink (ON + OFF) take?
8. 8.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) it starts again (c) it stops forever (d) the board breaks
9. 9.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
10. 10.🔍 Which sensor would you use to start a fan when hot? (a) a temperature sensor (b) a sound sensor (c) a distance sensor (d) a light sensor
11. 11.🌐 In an IoT system, which part carries the data? (a) Wi-Fi (b) phone app (c) sensor (d) microcontroller
12. 12.🔘 Which kind of switch closes near a magnet? (a) a slide switch (b) a reed switch (c) a toggle switch (d) a push button
13. 13.💡 4 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) No (b) Yes
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber band across the gap. Does the bulb glow? (a) Yes (b) No
15. 15.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) No (b) Yes
16. 16.True or false: a thermistor senses how hot it is. (a) False (b) True
17. 17.⏱️ repeat 5 times { buzzer ON; wait 600 ms; buzzer OFF; wait 400 ms }
    How many milliseconds does this take in all?
18. 18.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. Does bulb 1 glow? (a) Yes (b) No
19. 19.💡 A battery lights 2 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
20. 20.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) blinks 500 times (c) pauses for half a second (d) turns the LED off
21. 21.🔦 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
22. 22.🤖 Microcontroller or laptop: which one runs many apps at once? (a) laptop (b) microcontroller
23. 23.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 60 (d) 10
24. 24.🔘 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 OFF. Does the bulb glow? (a) No (b) Yes
25. 25.Which of these is not safe? (a) fly kites in open fields (b) fly a kite near wires (c) dry your hands first (d) take cells out after use
26. 26.⏱️ repeat 9 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
27. 27.🧮 A 68 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
28. 28.🔘 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 OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
29. 29.🔺 A current of 0.2 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
30. 30.True or false: to build with an adult near is not safe. (a) False (b) True
31. 31.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) it does not matter (d) none
32. 32.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
33. 33.📏 In the water-pipe picture of a circuit, resistance is like … (a) the water pressure (b) a bigger tank (c) the flow of water (d) a narrow pipe
34. 34.📏 How many ohms (Ω) is 0.6 kΩ?
35. 35.🔺 A current of 1 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) cell (c) resistor (d) switch
37. 37.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) prints 1 (d) adds 1 to count
38. 38.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
39. 39.🔁 count = 3
    while (count < 15) { count = count + 3 }
    How many times does the loop run?
40. 40.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 1 hour?

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