Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 325 · 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 I? (a) I = R ÷ V (b) I = V × R (c) I = V ÷ R (d) I = V + R
2. 2.🔁 repeat 4 times { repeat 3 times { beep } }
   How many beeps are there?
3. 3.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) make light (d) store charge briefly
4. 4.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
5. 5.🔘 A bulb and a cell are joined through 2 switches on 2 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
6. 6.True or false: a laptop has no screen of its own. (a) True (b) False
7. 7.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an output (d) an input
8. 8.🤖 if (temperature > 25) { fan ON } else { fan OFF }
   The temperature sensor reads 17 °C. What happens? (a) fan OFF (b) fan ON
9. 9.📶 A pin that reads a push button is set as … (a) an output (b) a resistor (c) a battery (d) an input
10. 10.🔁 count = 2
    repeat 9 times { count = count + 9 }
    What is count at the end?
11. 11.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) less than either one (d) more than either one
12. 12.🔌 Is a copper wire a conductor or an insulator? (a) a conductor (b) an insulator
13. 13.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 400 ms }
    How many times does the LED blink in 5 seconds?
14. 14.Which of these is safe? (a) use mains for a project (b) fly kites in open fields (c) poke things in a socket (d) throw cells in a fire
15. 15.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
16. 16.🌈 A resistor has the colour bands violet, red, red. What is its value in kilo-ohms (kΩ)? =
17. 17.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
18. 18.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 41 %. What happens? (a) pump OFF (b) pump ON
19. 19.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
20. 20.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 ampere (d) 1 volt
21. 21.🔍 Which is the odd one out? (a) a motor (b) a speaker (c) a servo motor (d) a push button
22. 22.Which of these is the process? (a) the fan starts (b) decide if soil is dry (c) a soil moisture reading (d) a temperature reading
23. 23.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe
24. 24.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
25. 25.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
26. 26.🔁 count = 2
    repeat 6 times { count = count + 4 }
    What is count at the end?
27. 27.🧩 Which part changes electrical energy into movement? (a) a fuse (b) an LED (c) a motor (d) a resistor
28. 28.True or false: a push button springs back when let go. (a) True (b) False
29. 29.Which of these is a good habit? (a) keep factory passwords (b) accept every permission (c) post your live location (d) log out of shared phones
30. 30.⚡ A 24 W device works on 24 V. What current does it take (in amperes)? =
31. 31.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “compare with the limit”? (a) switch the pump on/off (b) compare with the limit
32. 32.🔘 A bulb and a cell are joined through 4 switches on 4 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
33. 33.True or false: a dry cork is a conductor. (a) True (b) False
34. 34.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
35. 35.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
36. 36.💡 An LED is joined to a 5 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) does not light (c) may burn out
37. 37.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
38. 38.📶 Digital or analog: a door: open or shut? (a) digital (b) analog
39. 39.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) motor (b) junction (c) LED (d) switch
40. 40.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity

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