Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 106 · 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.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. Does bulb 1 glow? (a) No (b) Yes
2. 2.🤖 if (sound > 60) { red LED ON } else { green LED ON }
   The sound sensor reads 57. What happens? (a) red LED ON (b) green LED ON
3. 3.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
   How many times does the LED blink in 1 second?
4. 4.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 30 readings take?
5. 5.⚙️ Which actuator would you use to open a gate to 90°? (a) a servo motor (b) a buzzer (c) an LED (d) a motor
6. 6.🔘 Which kind of switch works only while pressed? (a) a push button (b) a toggle switch (c) a tilt switch (d) a reed switch
7. 7.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
8. 8.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
9. 9.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) plastic is an insulator (c) plastic makes current (d) to make them heavy
10. 10.🔍 Which is the odd one out? (a) use mains for a project (b) fly a kite near wires (c) open a phone charger (d) dry your hands first
11. 11.True or false: power is measured in amperes (A). (a) True (b) False
12. 12.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
13. 13.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
14. 14.🔍 Which is the odd one out? (a) check if temp > 30 (b) the fan starts (c) a buzzer beeps (d) the pump turns on
15. 15.🔺 A current of 2.5 A flows when 50 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.Which of these is measured in volts (V)? (a) current (b) resistance (c) the flow of charge (d) voltage
17. 17.⚡ Which tiny particles drift along a metal wire to carry the current? (a) electrons (b) photons (c) water drops (d) dust particles
18. 18.Which of these is an insulator? (a) an iron nail (b) a steel coin (c) a safety pin (d) a plastic straw
19. 19.🔘 A bulb and a cell are joined through 6 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
20. 20.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they get dimmer (d) they keep glowing
21. 21.True or false: a night lamp mainly makes sound. (a) True (b) False
22. 22.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 70 Ω resistor? (a) violet-black-black (b) grey-black-black (c) violet-black-brown (d) grey-violet-black
23. 23.🔌 Is an LED an input or an output for a microcontroller? (a) input (b) output
24. 24.Which of these is a risky habit? (a) set up with a parent (b) install software updates (c) set a strong password (d) keep factory passwords
25. 25.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
26. 26.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
27. 27.Which drawing is the symbol for a motor? (a) triangle, bar and arrows (b) triangle against a bar (c) a circle with an X in it (d) a circle with M inside
28. 28.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
29. 29.Which of these is true of a parallel circuit? (a) each gets the full volts (b) a break stops every bulb (c) bulbs share the voltage (d) a single current path
30. 30.🔺 A current of 25 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
32. 32.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) pick a problem to solve (b) build it with an adult (c) test it and fix it (d) list inputs and outputs
33. 33.⏱️ loop forever { LED ON; wait 450 ms; LED OFF; wait 150 ms }
    How many milliseconds does one blink (ON + OFF) take?
34. 34.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 24 %. What happens? (a) pump ON (b) pump OFF
35. 35.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a tilt switch (c) a push button (d) a slide switch
36. 36.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
37. 37.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) cell (b) resistor (c) ammeter (d) wire
38. 38.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 440 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
39. 39.Which of these wastes electricity? (a) unplug idle chargers (b) use daylight to read (c) use old filament bulbs (d) close the fridge quickly
40. 40.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 900 Ω resistor? (a) brown-white-brown (b) white-black-red (c) white-black-black (d) white-black-brown

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