Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 1 · 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 job needs a motion sensor? (a) stop a robot near walls (b) switch on with a clap (c) spot someone walking in (d) start a fan when hot
2. 2.🔐 Privacy for a smart device means controlling … (a) how loud it beeps (b) its colour (c) who can see your data (d) its battery size
3. 3.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 530 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
4. 4.True or false: the push of a cell is measured in volts (V). (a) False (b) True
5. 5.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
6. 6.Which job needs a rain sensor? (a) close a window in rain (b) keep an incubator warm (c) measure classroom noise (d) switch on lamps at dusk
7. 7.🔍 Which is the odd one out? (a) cover unused cameras (b) ignore update messages (c) post your live location (d) share camera links
8. 8.🔋 Does a water pump give electricity or use electricity? (a) uses electricity (b) gives electricity
9. 9.🔢 To get a sensor reading onto a phone, what comes right after “the board reads it”? (a) it is sent by Wi-Fi (b) the sensor measures (c) the app shows it (d) the cloud stores it
10. 10.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) False (b) True
11. 11.🔁 count = 2
    repeat 9 times { count = count + 2 }
    What is count at the end?
12. 12.🧩 Which component smooths a wobbly supply? (a) buzzer (b) transistor (c) fuse (d) capacitor
13. 13.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
14. 14.True or false: a capacitor smooths a wobbly supply. (a) False (b) True
15. 15.🔍 Which is the odd one out? (a) a brass key (b) a graphite rod (c) aluminium foil (d) a ceramic cup
16. 16.Which of these is the input? (a) a soil moisture reading (b) an LED lights up (c) a buzzer beeps (d) decide if soil is dry
17. 17.⚡ A 2.5 W device works on 5 V. What current does it take (in amperes)? =
18. 18.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 750 ms }
    How many milliseconds does one blink (ON + OFF) take?
19. 19.True or false: a reed switch slides side to side. (a) True (b) False
20. 20.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) the else part (c) both parts (d) neither part
21. 21.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
22. 22.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 8600 Ω resistor? (a) grey-blue-brown (b) grey-blue-red (c) blue-grey-red (d) grey-blue-orange
23. 23.True or false: “many paths for current” is true of a series circuit. (a) True (b) False
24. 24.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
25. 25.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 5 minutes?
26. 26.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I × R (d) V = I + R
27. 27.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) process (b) output (c) input
28. 28.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) motor (c) capacitor (d) voltmeter
29. 29.📏 How many amperes (A) is 860 mA? =
30. 30.🔐 Which is the strongest password for a home smart camera? (a) Tiger#Lamp42!Moon (b) 123456 (c) admin (d) password
31. 31.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
32. 32.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) a single current path (c) a break stops every bulb (d) many paths for current
33. 33.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it makes a sound (c) it changes colour (d) it does not light
34. 34.📏 How many watts (W) is 2.7 kW?
35. 35.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) blinks 500 times (d) turns the LED off
36. 36.📶 Digital or analog: the room temperature? (a) digital (b) analog
37. 37.🔍 Which is the odd one out? (a) change default passwords (b) ignore update messages (c) set a strong password (d) turn off unused gadgets
38. 38.🌈 A resistor has the colour bands orange, brown, orange. What is its value in kilo-ohms (kΩ)? =
39. 39.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) so all go off together (c) to make bulbs dim (d) to save copper only
40. 40.🤖 if (temperature > 25) { fan ON } else { fan OFF }
    The temperature sensor reads 24 °C. What happens? (a) fan ON (b) fan OFF

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