Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 340 · 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.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) type it all in (c) share it with friends (d) ask a parent first
2. 2.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🌈 A resistor has the colour bands brown, violet, black. What is its value (in ohms)?
4. 4.True or false: to poke things in a socket is safe. (a) True (b) False
5. 5.What does the cloud server do? (a) reads values, decides (b) shows data to you (c) stores data online (d) measures the real world
6. 6.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
7. 7.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
8. 8.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
9. 9.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
10. 10.Which of these wastes electricity? (a) use daylight to read (b) close the fridge quickly (c) set the AC to 24 °C (d) use old filament bulbs
11. 11.🔍 Which is the odd one out? (a) post your live location (b) read app permissions (c) change default passwords (d) set up with a parent
12. 12.🔁 count = 5
    while (count < 26) { count = count + 3 }
    How many times does the loop run?
13. 13.🔁 count = 5
    while (count < 23) { count = count + 3 }
    How many times does the loop run?
14. 14.📏 How many milliamperes (mA) is 1.67 A?
15. 15.🌈 A resistor has the colour bands grey, black, orange. What is its value in kilo-ohms (kΩ)? =
16. 16.Which of these is the input? (a) an alert on the phone (b) a buzzer beeps (c) a button press (d) count button presses
17. 17.🔌 A gap of dry air between two wires acts as … (a) an insulator (b) a conductor (c) a cell (d) a switch that is ON
18. 18.True or false: “a knob turned part way” is a digital signal. (a) False (b) True
19. 19.🔁 count = 0
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
20. 20.🔋 A 6 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
21. 21.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
22. 22.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
23. 23.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 40 Ω resistor? (a) yellow-black-brown (b) yellow-black-black (c) green-yellow-black (d) green-black-black
24. 24.🧮 A 2.8 V battery is joined to 8 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
25. 25.🔌 Is a water pump an input or an output for a microcontroller? (a) input (b) output
26. 26.🔺 A 5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
27. 27.⚙️ Which actuator would you use to show a status light? (a) a pump (b) a buzzer (c) a servo motor (d) an LED
28. 28.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) measure heat (d) spin a wheel
29. 29.🔍 A distance sensor sends a sound pulse and hears the echo 11 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
30. 30.Which of these mainly makes sound? (a) a toaster (b) a school bell (c) a table fan (d) a tube light
31. 31.⚡ A cell changes stored chemical energy into which kind of energy? (a) nuclear energy (b) wind energy (c) electrical energy (d) sound energy
32. 32.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
33. 33.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the output (c) the input (d) the battery
34. 34.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
35. 35.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
36. 36.🔍 Which is the odd one out? (a) a motion sensor signal (b) a soil moisture reading (c) a light level reading (d) compare with a limit
37. 37.What does the Wi-Fi link do? (a) measures the real world (b) stores data online (c) acts on a command (d) carries the data
38. 38.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
39. 39.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 10 (d) 100
40. 40.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a Wi-Fi smart plug (c) a plain table fan (d) a smart energy meter

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