Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 435 · 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.🧮 Resistors of 20 Ω, 330 Ω, 20 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a slide switch (c) a push button (d) a tilt switch
3. 3.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
4. 4.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
5. 5.⏱️ How many milliseconds is a wait of 0.5 seconds?
6. 6.🌈 In the resistor colour code, which number does yellow stand for?
7. 7.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
8. 8.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
   How many times does the LED blink in 10 seconds?
9. 9.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 250 ms }
   How many milliseconds does one blink (ON + OFF) take?
10. 10.🔺 A current of 1.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
11. 11.💡 4 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
12. 12.💡 5 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. Does bulb 5 glow? (a) No (b) Yes
13. 13.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
14. 14.🧮 A 3.5 V battery is joined to 4 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
15. 15.💡 What does LED stand for? (a) light energy dial (b) low energy device (c) large electric dial (d) light-emitting diode
16. 16.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
17. 17.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) only B is true (d) both A and B are true
18. 18.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
19. 19.⚠️ Is it safe to use small battery cells? (a) not safe (b) safe
20. 20.🔋 3 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
21. 21.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
22. 22.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) a fuse (c) a power source (d) an output
23. 23.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) junction (b) diode (c) resistor (d) voltmeter
24. 24.🔍 Which is the odd one out? (a) poke things in a socket (b) touch a fallen wire (c) fly a kite near wires (d) build with an adult near
25. 25.Which of these is measured in amperes (A)? (a) voltage (b) the push of a cell (c) current (d) power
26. 26.Which of these is an insulator? (a) a metal paper clip (b) a brass key (c) aluminium foil (d) a plastic ruler
27. 27.📏 Which unit measures voltage? (a) volt (V) (b) ohm (Ω) (c) ampere (A) (d) watt (W)
28. 28.🔁 x = 5
    repeat 2 times { x = x × 2 }
    What is x at the end?
29. 29.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 10 seconds?
30. 30.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
32. 32.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
33. 33.🌈 Which band is read first on a resistor? (a) the widest gap (b) the one nearest an end (c) the gold band (d) any band
34. 34.Which job needs a buzzer? (a) turn to an exact angle (b) beep an alarm (c) move water to plants (d) spin a robot’s wheels
35. 35.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
36. 36.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a tilt switch (c) a toggle switch (d) a push button
37. 37.📏 How many amperes (A) is 1670 mA? =
38. 38.True or false: “how loud a sound is” is an analog signal. (a) True (b) False
39. 39.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it changes colour (c) it lights brighter (d) it does not light
40. 40.🔺 A 9 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =

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