Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 13 · 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.True or false: current is measured in volts (V). (a) True (b) False
2. 2.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) used in house wiring (d) a break stops every bulb
3. 3.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = V + I (d) P = I ÷ V
4. 4.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V × I (d) R = V ÷ I
5. 5.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) junction (c) motor (d) ammeter
6. 6.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
7. 7.Which of these mainly gives out light? (a) a doorbell (b) a torch (c) an electric iron (d) a siren
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) in parallel (d) not joined
9. 9.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
10. 10.Which of these is the input? (a) the fan starts (b) count button presses (c) a soil moisture reading (d) decide if soil is dry
11. 11.🔌 Is a steel coin a conductor or an insulator? (a) an insulator (b) a conductor
12. 12.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
13. 13.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) never (c) when either is ON (d) only when both are OFF
14. 14.🔐 Who should decide which smart devices go in a child’s room? (a) an online stranger (b) the app’s adverts (c) a parent or guardian (d) nobody at all
15. 15.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) False (b) True
16. 16.🌈 A resistor has the colour bands brown, white, black. What is its value (in ohms)?
17. 17.🌈 A resistor has the colour bands violet, blue, yellow. What is its value in kilo-ohms (kΩ)? =
18. 18.🌈 A resistor has the colour bands brown, violet, orange. What is its value (in ohms)?
19. 19.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
20. 20.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
21. 21.🔋 3 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)? =
22. 22.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
23. 23.True or false: a diode limits the current. (a) True (b) False
24. 24.🔋 8 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
25. 25.🔺 A current of 0.2 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 53 %. What happens? (a) pump OFF (b) pump ON
27. 27.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes
28. 28.🔍 Which is the odd one out? (a) a plastic ruler (b) a graphite rod (c) a woollen thread (d) a cotton thread
29. 29.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
30. 30.🔍 An object is 289 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
31. 31.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
    The temperature is 38 °C. What is shown? (a) Warm (b) Hot (c) Cool
32. 32.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
33. 33.Which job needs a soil moisture sensor? (a) switch on lamps at dusk (b) keep an incubator warm (c) measure classroom noise (d) water a dry plant
34. 34.📶 Digital or analog: a button: pressed or not? (a) digital (b) analog
35. 35.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
36. 36.🔁 count = 4
    repeat 2 times { count = count + 7 }
    What is count at the end?
37. 37.🔍 Which sensor would you use to spot someone walking in? (a) a sound sensor (b) a distance sensor (c) a motion sensor (d) a temperature sensor
38. 38.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) dotted circles (c) straight lines (d) wavy lines
39. 39.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 10 (d) 1000
40. 40.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 200 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON

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