Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 665 · 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) many long-short pairs (c) a line lifted at a gap (d) two equal parallel lines
2. 2.⚡ Power tells us … (a) the size of a cell (b) the colour of light (c) the length of a wire (d) energy used each second
3. 3.🔋 A 9 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
4. 4.Which of these is true of a series circuit? (a) own switch for each bulb (b) each gets the full volts (c) used in house wiring (d) one bulb out, all go out
5. 5.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False
6. 6.Which of these is an IoT device? (a) a plain wall switch (b) a Wi-Fi doorbell camera (c) a plain table fan (d) a wind-up clock
7. 7.🔺 A current of 10 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) No (b) Yes
9. 9.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a smaller voltage (c) no voltage (d) a bigger voltage
10. 10.Which job needs a pump? (a) turn to an exact angle (b) move water to plants (c) spin a robot’s wheels (d) open a gate to 90°
11. 11.🔺 A current of 3 A flows when 60 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
13. 13.🔍 Which is the odd one out? (a) a battery torch (b) a plain table fan (c) a smart energy meter (d) a wind-up clock
14. 14.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
15. 15.🌈 A resistor has the colour bands green, black, brown. What is its value (in ohms)?
16. 16.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) switch (b) diode (c) motor (d) LED
17. 17.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 6 hours?
18. 18.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
19. 19.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
20. 20.🔋 Does a mobile phone give electricity or use electricity? (a) uses electricity (b) gives electricity
21. 21.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
22. 22.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
23. 23.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
24. 24.🧩 Which part changes electrical energy into movement? (a) an LED (b) a motor (c) a fuse (d) a resistor
25. 25.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
26. 26.True or false: to make a parking alarm, use a rain sensor. (a) True (b) False
27. 27.🔌 Is a motion sensor an input or an output for a microcontroller? (a) input (b) output
28. 28.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) a complete loop (d) one loose end
29. 29.What does a resistor do? (a) limits the current (b) smooths a wobbly supply (c) beeps for an alarm (d) senses how bright it is
30. 30.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
31. 31.True or false: “count button presses” is the input. (a) False (b) True
32. 32.True or false: a wooden stick is a conductor. (a) True (b) False
33. 33.Which of these wastes electricity? (a) unplug idle chargers (b) set the AC to 24 °C (c) run fans in empty rooms (d) close the fridge quickly
34. 34.True or false: to throw cells in a fire is not safe. (a) False (b) True
35. 35.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
36. 36.Which of these mainly makes movement? (a) a water heater (b) a night lamp (c) an exhaust fan (d) a loudspeaker
37. 37.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I + R (d) V = I ÷ R
38. 38.⚡ A 12 W device works on 24 V. What current does it take (in amperes)? =
39. 39.💡 2 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
40. 40.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No

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