Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 444 · 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.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7100 Ω resistor? (a) brown-violet-red (b) violet-brown-brown (c) violet-brown-orange (d) violet-brown-red
2. 2.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a wooden stick across the gap. Does the bulb glow? (a) Yes (b) No
3. 3.⏱️ repeat 4 times { buzzer ON; wait 400 ms; buzzer OFF; wait 700 ms }
   How many milliseconds does this take in all?
4. 4.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) the same voltage (c) a smaller voltage (d) no voltage
5. 5.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
6. 6.🔐 Is it a good or a risky habit to read app permissions? (a) risky habit (b) good habit
7. 7.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V × R (c) I = R ÷ V (d) I = V + R
9. 9.📏 How many ohms (Ω) is 2.2 kΩ?
10. 10.🌐 Is a plain table fan an IoT device? (a) not an IoT device (b) an IoT device
11. 11.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 890 Ω resistor? (a) grey-white-brown (b) grey-white-black (c) grey-white-red (d) white-grey-brown
12. 12.🔌 Is a motion sensor an input or an output for a microcontroller? (a) input (b) output
13. 13.Which of these has no microcontroller inside? (a) a microwave oven (b) a digital alarm clock (c) a smart watch (d) a hand pump
14. 14.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
16. 16.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 50 % (d) 5 %
17. 17.🔋 4 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
18. 18.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) diode (b) LED (c) wire (d) battery
19. 19.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 10 (d) 60
20. 20.True or false: the voltmeter is joined in series. (a) True (b) False
21. 21.🔁 count = 6
    repeat 9 times { count = count + 4 }
    What is count at the end?
22. 22.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 9 minutes?
23. 23.🧩 Which part changes electrical energy into movement? (a) an LED (b) a fuse (c) a motor (d) a resistor
24. 24.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
25. 25.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
26. 26.Which of these is an input? (a) a speaker (b) a buzzer (c) a motor (d) a motion sensor
27. 27.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
28. 28.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
29. 29.True or false: triangle, bar and arrows is the symbol for a capacitor. (a) False (b) True
30. 30.🔘 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 ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
31. 31.🔋 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)? =
32. 32.🧩 Which component boosts a small signal? (a) buzzer (b) potentiometer (c) transistor (d) resistor
33. 33.🔺 A current of 0.2 A flows when 0.6 V is joined across a resistor. What is its resistance (in ohms)?
34. 34.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
35. 35.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 540 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
36. 36.True or false: a ceramic cup is an insulator. (a) True (b) False
37. 37.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) little stars (c) straight lines (d) wavy lines
38. 38.🔺 A current of 25 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
39. 39.📏 How many watts (W) is 1 kW?
40. 40.🔘 A bulb and a cell are joined through 3 switches on 3 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?

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