Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 255 · 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.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = I ÷ V (d) R = V + I
2. 2.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
3. 3.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) low energy device (d) large electric dial
4. 4.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
5. 5.🧭 Which part of a microcontroller board restarts the program? (a) the power LED (b) the reset button (c) the pins (d) the main chip
6. 6.🌈 A resistor has the colour bands violet, blue, orange. What is its value in kilo-ohms (kΩ)? =
7. 7.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
8. 8.Which of these is safe? (a) touch a switch when wet (b) fly kites in open fields (c) touch a fallen wire (d) use a cable with cuts
9. 9.🧩 Which component makes a beeping sound? (a) resistor (b) buzzer (c) transistor (d) potentiometer
10. 10.🧩 Which component stores a little charge? (a) fuse (b) capacitor (c) LDR (d) resistor
11. 11.What does a reed switch do? (a) stays where you flip it (b) closes when tipped over (c) closes near a magnet (d) flips up or down
12. 12.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) stores a value (d) joins two wires
13. 13.⏱️ A program says “wait 5250 ms”. How many seconds is that? =
14. 14.⏱️ A program says “wait 250 ms”. How many seconds is that? =
15. 15.⚠️ Is it safe to use small battery cells? (a) not safe (b) safe
16. 16.True or false: a buzzer glows using little power. (a) False (b) True
17. 17.💡 3 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. How many bulbs glow?
18. 18.What does the microcontroller do? (a) measures the real world (b) reads values, decides (c) stores data online (d) acts on a command
19. 19.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
20. 20.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they get dimmer (c) they all go out (d) they keep glowing
21. 21.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
22. 22.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
23. 23.Which of these saves electricity? (a) close the fridge quickly (b) leave the TV on standby (c) iron one shirt at a time (d) run fans in empty rooms
24. 24.🧩 Which component senses how bright it is? (a) capacitor (b) LDR (c) resistor (d) transistor
25. 25.True or false: the push of a cell is measured in watts (W). (a) True (b) False
26. 26.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) always zero (d) less than either one
27. 27.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 1700 ms }
    How many times does the LED blink in 10 seconds?
28. 28.🔍 Which is the odd one out? (a) a ceiling fan (b) a night lamp (c) a traffic signal (d) a tube light
29. 29.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 33 °C. What is shown? (a) Warm (b) Cool (c) Hot
30. 30.🔍 Which sensor would you use to keep an incubator warm? (a) a sound sensor (b) a soil moisture sensor (c) a temperature sensor (d) a light sensor
31. 31.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
32. 32.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
33. 33.Which job is done by the power LED? (a) keeps the voltage steady (b) connect sensors and LEDs (c) brings power and code (d) shows the board is on
34. 34.🔢 To plan an electronics project, which is the FIRST step? (a) test it and fix it (b) build it with an adult (c) pick a problem to solve (d) draw the circuit diagram
35. 35.🧮 Resistors of 33 Ω, 220 Ω, 150 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
36. 36.🤖 Microcontroller or laptop: which one needs much more power? (a) microcontroller (b) laptop
37. 37.🧮 A 0.8 V battery is joined to 3 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
38. 38.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
39. 39.What does the actuator do? (a) stores data online (b) acts on a command (c) shows data to you (d) reads values, decides
40. 40.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1

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