Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 839 · 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.🔘 A bulb and a cell are joined through 6 switches on 6 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
2. 2.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 170 readings take?
3. 3.True or false: the voltmeter is joined across a part. (a) True (b) False
4. 4.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) No (b) Yes
5. 5.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
6. 6.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 650 ms }
   How many milliseconds does one blink (ON + OFF) take?
7. 7.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) Yes (b) No
8. 8.⚡ A 24 W device works on 24 V. What current does it take (in amperes)? =
9. 9.True or false: a tilt switch closes near a magnet. (a) False (b) True
10. 10.🔘 Which kind of switch closes near a magnet? (a) a push button (b) a slide switch (c) a reed switch (d) a toggle switch
11. 11.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
12. 12.Which of these is an output? (a) a motor (b) a turning knob (c) a motion sensor (d) a keypad
13. 13.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 53. What happens? (a) lamp OFF (b) lamp ON
14. 14.⚡ What does a night lamp mainly change electricity into? (a) sound (b) heat (c) movement (d) light
15. 15.🌐 Is a smart energy meter an IoT device? (a) an IoT device (b) not an IoT device
16. 16.True or false: a push button stays where you flip it. (a) True (b) False
17. 17.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the bulb is unscrewed (d) all wires are joined
18. 18.⚠️ Is it safe to throw cells in a fire? (a) safe (b) not safe
19. 19.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 170 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
20. 20.⚡ A 4.5 W device works on 1.5 V. What current does it take (in amperes)? =
21. 21.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 4.25 V supply. What current flows (in mA)?
22. 22.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) one bulb out, all go out (c) bulbs share the voltage (d) each gets the full volts
23. 23.🔋 Does a wind turbine give electricity or use electricity? (a) gives electricity (b) uses electricity
24. 24.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
25. 25.Which of these is the process? (a) a soil moisture reading (b) a button press (c) a buzzer beeps (d) compare with a limit
26. 26.🔋 How many 1.2 V cells must be joined in series to give 6 V?
27. 27.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) the longer line (c) both lines (d) neither line
28. 28.True or false: the ammeter measures voltage. (a) True (b) False
29. 29.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
30. 30.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
31. 31.True or false: “a door: open or shut” is an analog signal. (a) True (b) False
32. 32.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) plastic makes current (c) plastic is a conductor (d) to make them heavy
33. 33.⏱️ repeat 4 times { buzzer ON; wait 800 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
34. 34.🔍 Which is the odd one out? (a) a tube light (b) a loudspeaker (c) a siren (d) a buzzer
35. 35.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) how loud it beeps (d) who can see your data
36. 36.💡 3 identical bulbs are joined in series with a 4.5 V battery (ideal wires). How many volts does each bulb get? =
37. 37.🔋 Does a mobile phone give electricity or use electricity? (a) gives electricity (b) uses electricity
38. 38.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
39. 39.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 230 Ω resistor? (a) red-orange-black (b) red-orange-red (c) red-orange-brown (d) orange-red-brown
40. 40.🔍 Which is the odd one out? (a) a smart energy meter (b) an app-controlled bulb (c) a fitness band with app (d) a battery torch

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