Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 143 · 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 80 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
2. 2.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) one (c) two (d) none
3. 3.🧭 Which part of a microcontroller board runs the program? (a) the reset button (b) the voltage regulator (c) the power LED (d) the main chip
4. 4.Which job needs a distance sensor? (a) switch on with a clap (b) close a window in rain (c) stop a robot near walls (d) spot someone walking in
5. 5.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
6. 6.🔺 A 16 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
7. 7.True or false: a long and a short line is the symbol for a capacitor. (a) False (b) True
8. 8.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
9. 9.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
10. 10.🔋 6 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
11. 11.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) both of them (d) none
12. 12.🔍 Which is the odd one out? (a) share camera links (b) log out of shared phones (c) ignore update messages (d) keep factory passwords
13. 13.🔍 Which is the odd one out? (a) touch a switch when wet (b) use mains for a project (c) keep drinks far away (d) use a cable with cuts
14. 14.💡 3 identical bulbs are joined in series with a 4.5 V battery (ideal wires). How many volts does each bulb get? =
15. 15.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 5 % (d) 25 %
16. 16.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 1000 (c) 100 (d) 10
17. 17.True or false: to open a phone charger is safe. (a) True (b) False
18. 18.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) read the soil sensor (b) switch the pump on/off (c) wait a few seconds
19. 19.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
20. 20.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the bulb is unscrewed
21. 21.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
22. 22.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a push button (c) a slide switch (d) a tilt switch
23. 23.🤖 Where does the board keep its program when the power is off? (a) the power LED (b) the resistor (c) the USB cable (d) flash memory
24. 24.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the metal tip (c) the plastic handle (d) the bare end
25. 25.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
26. 26.📶 On a 5 V board, a pin set HIGH gives about … (a) 0 V (b) 50 V (c) 230 V (d) 5 V
27. 27.🧩 Which component limits the current? (a) thermistor (b) resistor (c) LDR (d) potentiometer
28. 28.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
29. 29.⚙️ Which actuator would you use to turn to an exact angle? (a) a buzzer (b) a servo motor (c) a motor (d) a display
30. 30.🔍 Which sensor would you use to switch on with a clap? (a) a motion sensor (b) a sound sensor (c) a distance sensor (d) a temperature sensor
31. 31.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a Wi-Fi doorbell camera (c) a pencil sharpener (d) a smart energy meter
32. 32.🧮 A 0.7 V battery is joined to 3 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
33. 33.Which drawing is the symbol for a battery? (a) a circle with A inside (b) a small empty box (c) two or more cell symbols (d) a long and a short line
34. 34.🧮 Four equal 400 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
35. 35.🔋 How many 3 V cells must be joined in series to give 15 V?
36. 36.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
37. 37.⚡ A cell changes stored chemical energy into which kind of energy? (a) wind energy (b) nuclear energy (c) sound energy (d) electrical energy
38. 38.🔌 Is a wooden stick a conductor or an insulator? (a) an insulator (b) a conductor
39. 39.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a Wi-Fi smart plug (c) a paper calendar (d) a fitness band with app
40. 40.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False

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