Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 509 · 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.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I
2. 2.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 60 (d) 1000
3. 3.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
4. 4.🔺 A current of 0.1 A flows when 0.5 V is joined across a resistor. What is its resistance (in ohms)?
5. 5.🌐 How does a home IoT device usually send its data to the app? (a) by post (b) through a candle (c) over Wi-Fi (d) by shouting
6. 6.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
7. 7.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 650 ms }
   How many milliseconds does one blink (ON + OFF) take?
8. 8.🔺 A current of 0.2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
9. 9.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) run fans in empty rooms (d) unplug idle chargers
10. 10.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
11. 11.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) LED (b) wire (c) motor (d) battery
12. 12.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the size of a cell (d) the colour of light
13. 13.True or false: to dry your hands first is not safe. (a) False (b) True
14. 14.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) dotted circles (c) little stars (d) wavy lines
15. 15.🔘 Which kind of switch flips up or down? (a) a push button (b) a slide switch (c) a tilt switch (d) a toggle switch
16. 16.True or false: resistance is measured in watts (W). (a) True (b) False
17. 17.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
18. 18.⚙️ Which actuator would you use to beep an alarm? (a) a motor (b) an LED (c) a servo motor (d) a buzzer
19. 19.🔺 A current of 20 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
20. 20.🔍 Which is the odd one out? (a) use a cable with cuts (b) fly kites in open fields (c) touch a switch when wet (d) touch a fallen wire
21. 21.Which of these is the input? (a) check if temp > 30 (b) a buzzer beeps (c) compare with a limit (d) a motion sensor signal
22. 22.💡 2 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
23. 23.🧭 Which part of a microcontroller board shows the board is on? (a) the USB port (b) the reset button (c) the pins (d) the power LED
24. 24.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 3 hours?
25. 25.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 370 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
27. 27.True or false: voltage is measured in amperes (A). (a) True (b) False
28. 28.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) tell it your passwords (c) put it in the bathroom (d) mute it when not in use
29. 29.🧩 A capacitor in a circuit can … (a) store charge briefly (b) measure heat (c) make light (d) spin a wheel
30. 30.Which of these mainly makes sound? (a) a street light (b) a rice cooker (c) a doorbell (d) a table fan
31. 31.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
32. 32.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a wire is cut
33. 33.⏱️ repeat 3 times { buzzer ON; wait 200 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
34. 34.What does a buzzer do? (a) smooths a wobbly supply (b) turns a fan or wheels (c) lets current go one way (d) beeps for an alarm
35. 35.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
36. 36.Which of these is not an IoT device? (a) a wind-up clock (b) a Wi-Fi doorbell camera (c) a smart energy meter (d) an app-controlled bulb
37. 37.⚡ What does an electric drill mainly change electricity into? (a) light (b) sound (c) movement (d) heat
38. 38.Which drawing is the symbol for a motor? (a) a small empty box (b) a circle with M inside (c) a long and a short line (d) two equal parallel lines
39. 39.🔐 Is it a good or a risky habit to accept every permission? (a) good habit (b) risky habit
40. 40.🧮 Four equal 400 Ω resistors are joined in parallel. What is the total resistance (in ohms)?

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