Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 943 · 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 current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
2. 2.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 LOW
   set pin 7 LOW
   set pin 7 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
3. 3.🔍 Which is the odd one out? (a) a buzzer (b) a speaker (c) an LED (d) a push button
4. 4.True or false: a microwave oven usually has a microcontroller inside. (a) False (b) True
5. 5.🔺 A current of 10 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
6. 6.🔺 A 5 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
7. 7.Which job is done by the reset button? (a) connect sensors and LEDs (b) brings power and code (c) restarts the program (d) keeps the voltage steady
8. 8.💡 6 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
9. 9.⚡ A 9 W device works on 9 V. What current does it take (in amperes)? =
10. 10.🔺 A current of 0.2 A flows when 1.6 V is joined across a resistor. What is its resistance (in ohms)?
11. 11.Which of these is an insulator? (a) a graphite rod (b) a plastic ruler (c) a copper wire (d) aluminium foil
12. 12.Which job needs a servo motor? (a) move water to plants (b) open a gate to 90° (c) beep an alarm (d) show a status light
13. 13.True or false: two equal parallel lines is the symbol for a capacitor. (a) False (b) True
14. 14.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🔍 Which is the odd one out? (a) a rubber eraser (b) a plastic straw (c) a woollen thread (d) a steel spoon
16. 16.True or false: to switch on lamps at dusk, use a light sensor. (a) True (b) False
17. 17.🤖 What is a microcontroller? (a) a big desktop computer (b) a computer on one chip (c) a type of battery (d) a kind of bulb
18. 18.True or false: a push button closes when tipped over. (a) False (b) True
19. 19.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 580 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
20. 20.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 220 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
21. 21.What does a buzzer do? (a) is a resistance knob (b) has coloured bands (c) makes a beeping sound (d) stores a little charge
22. 22.🔐 Why install updates on IoT devices? (a) they delete the Wi-Fi (b) they make it heavier (c) they change the colour (d) they fix security holes
23. 23.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
24. 24.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets smaller (c) stays the same (d) gets bigger
25. 25.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
26. 26.⏱️ How many milliseconds is a wait of 1.2 seconds?
27. 27.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
28. 28.🌐 Is a wind-up clock an IoT device? (a) an IoT device (b) not an IoT device
29. 29.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is ON and D is ON. Does the bulb glow? (a) No (b) Yes
30. 30.Which job is done by the USB port? (a) runs the program (b) keeps the voltage steady (c) brings power and code (d) connect sensors and LEDs
31. 31.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) closed (d) open
32. 32.What does a capacitor do? (a) blows if current is high (b) senses how bright it is (c) boosts a small signal (d) smooths a wobbly supply
33. 33.True or false: to cover unused cameras is a good habit. (a) True (b) False
34. 34.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 260 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
35. 35.Which of these usually has a microcontroller inside? (a) a hand pump (b) a smart watch (c) a wind-up toy (d) a plain wall switch
36. 36.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
37. 37.Which of these is not safe? (a) dry your hands first (b) stay away from pylons (c) keep drinks far away (d) touch a fallen wire
38. 38.🔐 Is it a good or a risky habit to share camera links? (a) good habit (b) risky habit
39. 39.Which of these is an IoT device? (a) a paper calendar (b) an app-controlled bulb (c) a plain table fan (d) a plain wall switch
40. 40.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False

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