Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 479 · 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.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
2. 2.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a tilt switch (c) a slide switch (d) a toggle switch
3. 3.🧩 Which component limits the current? (a) resistor (b) fuse (c) capacitor (d) potentiometer
4. 4.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
5. 5.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 150 readings take?
6. 6.Which drawing is the symbol for a motor? (a) a circle with M inside (b) a circle with a cross (c) a plain rectangle (d) a circle with an X in it
7. 7.⚠️ Is it safe to fly kites in open fields? (a) safe (b) not safe
8. 8.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the app shows it (b) the sensor measures (c) the board reads it (d) it is sent by Wi-Fi
9. 9.🔁 count = 2
   repeat 2 times { count = count + 3 }
   What is count at the end?
10. 10.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 6200 Ω resistor? (a) red-blue-red (b) blue-red-brown (c) blue-red-red (d) blue-red-orange
11. 11.🔋 Does an air conditioner give electricity or use electricity? (a) uses electricity (b) gives electricity
12. 12.🧮 Three equal 75 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
13. 13.True or false: to stop a robot near walls, use a distance sensor. (a) True (b) False
14. 14.🔺 A current of 2.5 A flows when 37.5 V is joined across a resistor. What is its resistance (in ohms)?
15. 15.True or false: a fuse blows if current is high. (a) True (b) False
16. 16.⚠️ Who should be with you when you build a circuit? (a) a stranger online (b) a younger child (c) nobody (d) a trusted adult
17. 17.⏱️ repeat 10 times { buzzer ON; wait 200 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
18. 18.True or false: “HIGH or LOW only” is a digital signal. (a) False (b) True
19. 19.Which of these wastes electricity? (a) use LED lamps (b) run fans in empty rooms (c) switch off empty rooms (d) close the fridge quickly
20. 20.True or false: the voltmeter is joined across a part. (a) False (b) True
21. 21.🔋 What is a battery? (a) one single wire (b) a kind of bulb (c) two or more cells joined (d) a switch with a lid
22. 22.🔍 Which is the odd one out? (a) use daylight to read (b) unplug idle chargers (c) switch off empty rooms (d) leave fridge door open
23. 23.🌈 A resistor has the colour bands orange, red, red. What is its value in kilo-ohms (kΩ)? =
24. 24.🔍 Which is the odd one out? (a) a doorbell (b) a loudspeaker (c) a water heater (d) a siren
25. 25.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 13 Ω resistor? (a) brown-orange-brown (b) red-orange-black (c) brown-orange-black (d) orange-brown-black
26. 26.True or false: “the pump turns on” is the process. (a) False (b) True
27. 27.Which of these is the output? (a) count button presses (b) a soil moisture reading (c) an LED lights up (d) a motion sensor signal
28. 28.⚠️ Is it safe to dry your hands first? (a) not safe (b) safe
29. 29.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
30. 30.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
31. 31.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
32. 32.Which job is done by the USB port? (a) restarts the program (b) brings power and code (c) connect sensors and LEDs (d) keeps the voltage steady
33. 33.🔘 Which kind of switch slides side to side? (a) a tilt switch (b) a push button (c) a slide switch (d) a toggle switch
34. 34.🌐 Is a paper calendar an IoT device? (a) not an IoT device (b) an IoT device
35. 35.True or false: “the room temperature” is a digital signal. (a) True (b) False
36. 36.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔺 A current of 1 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic ruler across the gap. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: “the pump turns on” is the input. (a) False (b) True
40. 40.True or false: two or more cell symbols is the symbol for a voltmeter. (a) True (b) False

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