Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 218 · 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.True or false: a doorbell mainly gives out light. (a) False (b) True
2. 2.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 4 V supply. What current flows (in mA)?
3. 3.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔍 Which is the odd one out? (a) a brass key (b) an iron nail (c) a ceramic cup (d) a graphite rod
5. 5.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 1 minute?
6. 6.🤖 Does a plain wall switch usually have a microcontroller inside? (a) Yes (b) No
7. 7.🌈 In the resistor colour code, which number does white stand for?
8. 8.🧮 Resistors of 68 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.🔐 Is it a good or a risky habit to cover unused cameras? (a) risky habit (b) good habit
10. 10.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
11. 11.🌈 In the resistor colour code, which number does orange stand for?
12. 12.💡 4 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 1 and 3 are taken out of their holders. How many bulbs glow?
13. 13.🌐 Is an app-controlled bulb an IoT device? (a) an IoT device (b) not an IoT device
14. 14.True or false: voltage is measured in watts (W). (a) False (b) True
15. 15.🔘 Which kind of switch stays where you flip it? (a) a toggle switch (b) a slide switch (c) a push button (d) a reed switch
16. 16.⚠️ Is it safe to touch a fallen wire? (a) safe (b) not safe
17. 17.Which drawing is the symbol for a wire? (a) a small empty box (b) a straight line (c) one tall, one short bar (d) a line lifted at a gap
18. 18.Which of these mainly gives out heat? (a) a room heater (b) a ceiling fan (c) an LED lamp (d) an electric drill
19. 19.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 250 ms }
    How many milliseconds does one blink (ON + OFF) take?
20. 20.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 6 seconds?
21. 21.Which of these is a conductor? (a) a rubber eraser (b) a rubber band (c) a wooden stick (d) a steel coin
22. 22.⚡ A device works on 12 V and takes 1.5 A. What is its power (in watts)? =
23. 23.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) an IoT device (b) not an IoT device
24. 24.🧮 A 7 V battery is joined to 6 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
25. 25.🔐 Why install updates on IoT devices? (a) they change the colour (b) they delete the Wi-Fi (c) they fix security holes (d) they make it heavier
26. 26.True or false: the ammeter measures current. (a) False (b) True
27. 27.🌈 In the resistor colour code, which number does blue stand for?
28. 28.Which of these is measured in amperes (A)? (a) power (b) resistance (c) current (d) the push of a cell
29. 29.🧮 A 17 V battery is joined to 5 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
30. 30.🔍 Which sensor would you use to spot someone walking in? (a) a rain sensor (b) a motion sensor (c) a gas sensor (d) a temperature sensor
31. 31.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.Which of these is a good habit? (a) post your live location (b) ignore update messages (c) install software updates (d) keep factory passwords
33. 33.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the pins (b) the USB port (c) the power LED (d) the voltage regulator
34. 34.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) both are false (c) only A is true (d) only B is true
35. 35.Which of these uses electricity? (a) a refrigerator (b) a wind turbine (c) a cell (d) a solar panel
36. 36.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
38. 38.True or false: one tall, one short bar is the symbol for a switch. (a) True (b) False
39. 39.⚠️ Is it safe to fly kites in open fields? (a) not safe (b) safe
40. 40.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is ON, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No

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