Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 602 · 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 drawing is the symbol for a diode? (a) two equal parallel lines (b) triangle against a bar (c) a circle with V inside (d) a plain rectangle
2. 2.Which of these is true of a series circuit? (a) many paths for current (b) used in house wiring (c) a single current path (d) own switch for each bulb
3. 3.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
4. 4.True or false: “a tilt switch: on or off” is an analog signal. (a) False (b) True
5. 5.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
6. 6.True or false: to warn of a gas leak, use a rain sensor. (a) False (b) True
7. 7.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
8. 8.True or false: “a soil moisture reading” is the input. (a) False (b) True
9. 9.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 360 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
10. 10.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 520 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
11. 11.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) LED (b) cell (c) voltmeter (d) resistor
12. 12.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = I ÷ V (d) R = V × I
13. 13.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) True (b) False
14. 14.True or false: to use old filament bulbs saves electricity. (a) False (b) True
15. 15.🔺 A current of 2 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) never (c) only when both are ON (d) only when both are OFF
17. 17.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 34 Ω resistor? (a) orange-yellow-brown (b) yellow-yellow-black (c) yellow-orange-black (d) orange-yellow-black
18. 18.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) it spoils the paint (c) water makes it cold (d) water carries current
19. 19.🌈 A resistor has the colour bands brown, orange, brown. What is its value (in ohms)?
20. 20.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) neither line (c) the shorter line (d) both lines
21. 21.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
22. 22.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) straight lines (d) dotted circles
23. 23.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is ON and B is OFF. Does the bulb glow? (a) No (b) Yes
24. 24.🔍 A distance sensor sends a sound pulse and hears the echo 5 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
25. 25.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 volt
26. 26.📏 Which unit measures voltage? (a) ampere (A) (b) ohm (Ω) (c) volt (V) (d) watt (W)
27. 27.🔺 A current of 0.1 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
28. 28.True or false: to use a cable with cuts is not safe. (a) True (b) False
29. 29.⏱️ A program says “wait 3750 ms”. How many seconds is that? =
30. 30.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) gets smaller (d) stays the same
31. 31.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 6 hours?
32. 32.🧩 Which component makes things spin? (a) LDR (b) resistor (c) motor (d) diode
33. 33.🔺 A current of 0.25 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
34. 34.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put an iron nail across the gap. Does the bulb glow? (a) No (b) Yes
35. 35.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a soil moisture sensor (c) a light sensor (d) a rain sensor
36. 36.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
37. 37.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the board reads it (b) the app shows it (c) the cloud stores it (d) it is sent by Wi-Fi
38. 38.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) open (d) closed
39. 39.Which of these is an output? (a) a sound sensor (b) a turning knob (c) a motor (d) a motion sensor
40. 40.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)

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