Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 440 · 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 tiny particles drift along a metal wire to carry the current? (a) electrons (b) photons (c) water drops (d) dust particles
2. 2.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V ÷ I (d) R = V + I
3. 3.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
4. 4.⚠️ Is it safe to fly a kite near wires? (a) safe (b) not safe
5. 5.💡 What happens if an LED is put in backwards? (a) it changes colour (b) it lights brighter (c) it makes a sound (d) it does not light
6. 6.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to make it brighter (c) to store charge (d) to change its colour
7. 7.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 450 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
8. 8.⏱️ A program says “wait 7750 ms”. How many seconds is that? =
9. 9.Which of these mainly makes sound? (a) an electric iron (b) a night lamp (c) a loudspeaker (d) a room heater
10. 10.🔋 A 6 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
11. 11.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) compare with the limit (b) read the soil sensor (c) wait a few seconds (d) switch the pump on/off
12. 12.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
13. 13.🌈 In the resistor colour code, which number does orange stand for?
14. 14.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
15. 15.🔍 Which is the odd one out? (a) a battery torch (b) a plain wall switch (c) a Wi-Fi weather station (d) a wind-up clock
16. 16.⚡ Which formula gives electric power? (a) P = V × I (b) P = V + I (c) P = I ÷ V (d) P = V ÷ I
17. 17.🔍 Which is the odd one out? (a) keep factory passwords (b) install software updates (c) set up with a parent (d) log out of shared phones
18. 18.🔘 A bulb and a cell are joined through 4 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
19. 19.🤖 Does a microwave oven usually have a microcontroller inside? (a) No (b) Yes
20. 20.Which job is done by the voltage regulator? (a) connect sensors and LEDs (b) keeps the voltage steady (c) restarts the program (d) brings power and code
21. 21.Which drawing is the symbol for a diode? (a) a small empty box (b) a plain rectangle (c) triangle against a bar (d) a circle with A inside
22. 22.Which job is done by the USB port? (a) connect sensors and LEDs (b) brings power and code (c) keeps the voltage steady (d) restarts the program
23. 23.🔘 Which kind of switch closes when tipped over? (a) a slide switch (b) a push button (c) a reed switch (d) a tilt switch
24. 24.🔍 Which is the odd one out? (a) cover unused cameras (b) log out of shared phones (c) set up with a parent (d) share camera links
25. 25.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 1 cm. What happens? (a) buzzer beeps (b) buzzer is silent
26. 26.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V + R (d) I = V × R
27. 27.True or false: “a temperature reading” is the input. (a) False (b) True
28. 28.🔋 How many volts does one ordinary torch cell give? (a) 1.5 V (b) 0.5 V (c) 230 V (d) 15 V
29. 29.🔺 A current of 1 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
30. 30.True or false: “HIGH or LOW only” is a digital signal. (a) False (b) True
31. 31.⏱️ How many milliseconds is a wait of 3.1 seconds?
32. 32.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 65000 Ω resistor? (a) green-blue-orange (b) blue-green-yellow (c) blue-green-red (d) blue-green-orange
33. 33.Which drawing is the symbol for a capacitor? (a) triangle, bar and arrows (b) a circle with V inside (c) two or more cell symbols (d) two equal parallel lines
34. 34.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) never (c) only when both are ON (d) when either is ON
35. 35.🔋 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)? =
36. 36.True or false: a siren mainly makes sound. (a) False (b) True
37. 37.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.What does a resistor do? (a) is a resistance knob (b) beeps for an alarm (c) limits the current (d) turns a fan or wheels
39. 39.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
40. 40.Which of these is a conductor? (a) a cotton thread (b) a paper strip (c) a brass key (d) a plastic ruler

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