Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 358 · 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.Which drawing is the symbol for a switch? (a) a small empty box (b) a dot where wires meet (c) a line lifted at a gap (d) many long-short pairs
2. 2.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
3. 3.🧩 Which component makes things spin? (a) diode (b) motor (c) transistor (d) fuse
4. 4.🌈 A resistor has the colour bands blue, red, yellow. What is its value in kilo-ohms (kΩ)? =
5. 5.🔁 What does “count = count + 1” do? (a) takes 1 away (b) prints 1 (c) adds 1 to count (d) sets count to 1
6. 6.Which of these uses electricity? (a) a bicycle dynamo (b) a mobile phone (c) a solar panel (d) a power station
7. 7.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
8. 8.🔺 A current of 0.5 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.True or false: a safety pin is an insulator. (a) False (b) True
10. 10.🔺 A current of 40 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
11. 11.Which of these gives us electricity? (a) a television (b) a mobile phone (c) a washing machine (d) a solar panel
12. 12.🧩 Which component makes a beeping sound? (a) LED (b) resistor (c) capacitor (d) buzzer
13. 13.🌈 In the resistor colour code, which number does grey stand for?
14. 14.True or false: the voltmeter measures current. (a) False (b) True
15. 15.⏱️ A program says “wait 5000 ms”. How many seconds is that? =
16. 16.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
17. 17.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a buzzer (c) a diode (d) a capacitor
18. 18.Which of these usually has a microcontroller inside? (a) a candle (b) a smart watch (c) a wind-up toy (d) a spinning top
19. 19.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
20. 20.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
21. 21.🧾 A 1000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
22. 22.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) switch (b) ammeter (c) junction (d) cell
23. 23.Which of these has no microcontroller inside? (a) a digital alarm clock (b) a bicycle bell (c) a TV remote (d) a washing machine
24. 24.🧩 Which part changes electrical energy into movement? (a) a motor (b) a resistor (c) a fuse (d) an LED
25. 25.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a buzzer (b) a motor (c) a servo motor (d) a pump
26. 26.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
27. 27.🔍 Which is the odd one out? (a) reuse one password (b) share the Wi-Fi key (c) ignore update messages (d) share only needed data
28. 28.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) switch off empty rooms (d) iron one shirt at a time
29. 29.Which of these is the input? (a) decide if soil is dry (b) a light level reading (c) count button presses (d) the fan starts
30. 30.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put an iron nail across the gap. Does the bulb glow? (a) Yes (b) No
31. 31.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 35 %. What happens? (a) pump OFF (b) pump ON
32. 32.🔘 When a switch is ON, the circuit is … (a) closed (b) broken (c) open (d) cut
33. 33.🔋 What is a battery? (a) a switch with a lid (b) one single wire (c) two or more cells joined (d) a kind of bulb
34. 34.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a toggle switch (c) a tilt switch (d) a slide switch
35. 35.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 130 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
36. 36.🔘 A bulb and a cell are joined through 2 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
37. 37.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
38. 38.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) bigger (d) smaller
39. 39.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
40. 40.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a paper strip across the gap. Does the bulb glow? (a) Yes (b) No

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