Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 752 · 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 a circuit diagram, which part is drawn as a circle with a cross? (a) cell (b) resistor (c) capacitor (d) bulb
2. 2.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
3. 3.What does a reed switch do? (a) slides side to side (b) springs back when let go (c) closes near a magnet (d) works only while pressed
4. 4.🔁 total = 0
   for i = 1 to 11 { total = total + i }
   What is total at the end?
5. 5.🧮 Resistors of 100 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
6. 6.True or false: a toaster mainly gives out heat. (a) False (b) True
7. 7.⚡ A 0.6 W device works on 6 V. What current does it take (in amperes)? =
8. 8.Which of these is measured in watts (W)? (a) the push of a cell (b) power (c) current (d) the flow of charge
9. 9.🔦 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) Yes (b) No
10. 10.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
11. 11.⏱️ How many milliseconds is a wait of 2 seconds?
12. 12.🧮 An 8 V battery is joined to 3 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
13. 13.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
14. 14.🔋 How many 1.2 V cells must be joined in series to give 4.8 V?
15. 15.💡 An LED is joined to a 6 V battery through a 470 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) may burn out (b) lights up (c) does not light
16. 16.⚠️ Is it safe to use mains for a project? (a) not safe (b) safe
17. 17.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a motor (b) a buzzer (c) a pump (d) an LED
18. 18.⚡ A solar panel changes which kind of energy into electricity? (a) chemical energy (b) sound energy (c) light energy (d) wind energy
19. 19.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
20. 20.🔺 A 3 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
21. 21.Which of these is an output? (a) a keypad (b) a turning knob (c) a motor (d) a push button
22. 22.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
23. 23.⚡ What does a buzzer mainly change electricity into? (a) movement (b) light (c) heat (d) sound
24. 24.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the gold band (d) the widest gap
25. 25.Which of these mainly gives out light? (a) a night lamp (b) a ceiling fan (c) a doorbell (d) a school bell
26. 26.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
27. 27.🤖 if (temperature > 25) { fan ON } else { fan OFF }
    The temperature sensor reads 17 °C. What happens? (a) fan OFF (b) fan ON
28. 28.🌈 In the resistor colour code, which number does white stand for?
29. 29.🔦 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
30. 30.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
31. 31.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire is cut (d) the switch is ON
32. 32.🤖 if (temperature > 30) { fan ON } else { fan OFF }
    The temperature sensor reads 25 °C. What happens? (a) fan OFF (b) fan ON
33. 33.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to change its colour (c) to limit the current (d) to store charge
34. 34.Which of these saves electricity? (a) use old filament bulbs (b) iron one shirt at a time (c) leave the TV on standby (d) switch off empty rooms
35. 35.🌈 In the resistor colour code, which number does red stand for?
36. 36.🔌 Is a safety pin a conductor or an insulator? (a) an insulator (b) a conductor
37. 37.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) True (b) False
38. 38.🔍 A distance sensor sends a sound pulse and hears the echo 1 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
39. 39.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) battery (b) junction (c) cell (d) switch
40. 40.Which of these is true of a series circuit? (a) each gets the full volts (b) own switch for each bulb (c) one out, the rest glow (d) one bulb out, all go out

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