Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 291 · 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.🤖 if (sound > 60) { red LED ON } else { green LED ON }
   The sound sensor reads 66. What happens? (a) red LED ON (b) green LED ON
2. 2.Which of these is not safe? (a) dry your hands first (b) keep drinks far away (c) use small battery cells (d) use a cable with cuts
3. 3.🔍 Which is the odd one out? (a) a tube light (b) a street light (c) a traffic signal (d) a ceiling fan
4. 4.Which drawing is the symbol for a voltmeter? (a) a plain rectangle (b) triangle against a bar (c) a circle with V inside (d) a straight line
5. 5.🔍 Which is the odd one out? (a) install software updates (b) share only needed data (c) read app permissions (d) ignore update messages
6. 6.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
7. 7.🔋 Does an air conditioner give electricity or use electricity? (a) gives electricity (b) uses electricity
8. 8.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 4 V supply. What current flows (in mA)?
9. 9.🔁 x = 4
   repeat 2 times { x = x × 2 }
   What is x at the end?
10. 10.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
11. 11.What does a capacitor do? (a) makes a beeping sound (b) limits the current (c) makes things spin (d) stores a little charge
12. 12.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) leave fridge door open (d) close the fridge quickly
13. 13.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a graphite rod across the gap. Does the bulb glow? (a) Yes (b) No
14. 14.🌐 Is a battery torch an IoT device? (a) an IoT device (b) not an IoT device
15. 15.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
16. 16.🧩 Which component has coloured bands? (a) LED (b) resistor (c) potentiometer (d) thermistor
17. 17.🔍 Which is the odd one out? (a) use old filament bulbs (b) use daylight to read (c) leave fridge door open (d) iron one shirt at a time
18. 18.🧩 Which component turns a fan or wheels? (a) fuse (b) LDR (c) resistor (d) motor
19. 19.True or false: current is measured in amperes (A). (a) True (b) False
20. 20.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 12 °C. What is shown? (a) Hot (b) Cool (c) Warm
21. 21.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) Yes (b) No
22. 22.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 12 seconds?
23. 23.Which of these has no microcontroller inside? (a) a wind-up toy (b) a digital alarm clock (c) a TV remote (d) a digital thermometer
24. 24.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
25. 25.⏱️ A program says “wait 7250 ms”. How many seconds is that? =
26. 26.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
27. 27.🔍 Which is the odd one out? (a) reuse one password (b) log out of shared phones (c) share the Wi-Fi key (d) share camera links
28. 28.🌈 A resistor has the colour bands blue, orange, red. What is its value (in ohms)?
29. 29.🔺 A 4.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
30. 30.True or false: “the pump turns on” is the process. (a) False (b) True
31. 31.Which of these is safe? (a) touch a fallen wire (b) keep drinks far away (c) use a cable with cuts (d) use mains for a project
32. 32.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) neither part (c) the else part (d) the if part
33. 33.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) both lines (c) neither line (d) the shorter line
34. 34.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 29 °C. What happens? (a) fan ON (b) fan OFF
35. 35.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) to save copper only (c) each gets full voltage (d) so all go off together
36. 36.💡 In a series circuit, how many paths does the current have? (a) none (b) one (c) two (d) one for each bulb
37. 37.Which of these is a conductor? (a) a wooden stick (b) an iron nail (c) a woollen thread (d) a cotton thread
38. 38.🔺 A 20 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
39. 39.⏱️ A program says “wait 7750 ms”. How many seconds is that? =
40. 40.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) less than either one (d) always zero

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