Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 631 · 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.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) smaller (d) stay the same
2. 2.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 150 ms }
   How many times does the LED blink in 9 seconds?
3. 3.Which job needs a display? (a) show a status light (b) open a gate to 90° (c) turn to an exact angle (d) show the temperature
4. 4.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
5. 5.🔺 A current of 1 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
6. 6.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 17 °C. What is shown? (a) Cool (b) Warm (c) Hot
7. 7.🔍 Which is the odd one out? (a) post your live location (b) log out of shared phones (c) reuse one password (d) ignore update messages
8. 8.⚡ A 1.25 W device works on 5 V. What current does it take (in amperes)? =
9. 9.What does a slide switch do? (a) slides side to side (b) flips up or down (c) springs back when let go (d) closes near a magnet
10. 10.🤖 “if (A AND B)” is true when … (a) only A is true (b) only B is true (c) both are false (d) both A and B are true
11. 11.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) blinks 500 times (d) pauses for half a second
12. 12.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) two (c) none (d) one
13. 13.Which of these has no microcontroller inside? (a) a TV remote (b) a washing machine (c) a candle (d) a microwave oven
14. 14.📶 Digital or analog: how loud a sound is? (a) digital (b) analog
15. 15.True or false: a straight line is the symbol for a wire. (a) False (b) True
16. 16.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
17. 17.True or false: an LDR has coloured bands. (a) True (b) False
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
19. 19.Which of these has no microcontroller inside? (a) a microwave oven (b) a TV remote (c) a digital alarm clock (d) a hand pump
20. 20.📶 How many states can a digital pin have? (a) one (b) ten (c) two (d) a thousand
21. 21.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 3.5 V supply. What current flows (in mA)?
22. 22.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
23. 23.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 549. What happens? (a) lamp ON (b) lamp OFF
24. 24.🔁 count = 9
    repeat 2 times { count = count + 2 }
    What is count at the end?
25. 25.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) use daylight to read (d) use old filament bulbs
26. 26.📏 How many ohms (Ω) is 9.2 kΩ?
27. 27.🌈 In the resistor colour code, which number does yellow stand for?
28. 28.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
29. 29.🔍 Which is the odd one out? (a) keep drinks far away (b) dry your hands first (c) use small battery cells (d) touch a switch when wet
30. 30.🔁 count = 4
    repeat 2 times { count = count + 5 }
    What is count at the end?
31. 31.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
32. 32.✏️ In a circuit diagram, which part is drawn as a straight line? (a) diode (b) wire (c) ammeter (d) LED
33. 33.🤖 Microcontroller or laptop: which one uses very little power? (a) microcontroller (b) laptop
34. 34.⏱️ repeat 8 times { buzzer ON; wait 100 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
35. 35.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) to hide the circuit (c) symbols are heavier (d) to make it colourful
36. 36.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
37. 37.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
38. 38.Which of these is a risky habit? (a) set up with a parent (b) install software updates (c) share camera links (d) log out of shared phones
39. 39.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 17 °C. What is shown? (a) Hot (b) Cool (c) Warm
40. 40.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True

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