Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 949 · 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.🧮 Five equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
2. 2.Which drawing is the symbol for a voltmeter? (a) a circle with an X in it (b) a small empty box (c) a circle with V inside (d) a long and a short line
3. 3.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) both lines (c) the longer line (d) the shorter line
4. 4.True or false: to take cells out after use is safe. (a) False (b) True
5. 5.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) an oil lamp (d) a candle
6. 6.🧩 Which component senses how bright it is? (a) LDR (b) resistor (c) fuse (d) motor
7. 7.⚡ What does a water heater mainly change electricity into? (a) heat (b) sound (c) movement (d) light
8. 8.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
9. 9.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) process (b) output (c) input
10. 10.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
11. 11.🔦 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
12. 12.🔌 Is a plastic ruler a conductor or an insulator? (a) an insulator (b) a conductor
13. 13.⚠️ Who should be with you when you build a circuit? (a) nobody (b) a younger child (c) a stranger online (d) a trusted adult
14. 14.🧮 A 2.6 V battery is joined to 10 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
15. 15.🌈 In the resistor colour code, which number does brown stand for?
16. 16.True or false: a tilt switch springs back when let go. (a) True (b) False
17. 17.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they all go out (c) they keep glowing (d) they explode
18. 18.✏️ In a circuit diagram, which part is drawn as a circle with V inside? (a) resistor (b) voltmeter (c) wire (d) battery
19. 19.🔍 Which sensor would you use to open blinds at sunrise? (a) a light sensor (b) a soil moisture sensor (c) a gas sensor (d) a distance sensor
20. 20.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 32 °C. What is shown? (a) Cool (b) Hot (c) Warm
21. 21.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 447. What happens? (a) lamp OFF (b) lamp ON
22. 22.What does the phone app do? (a) carries the data (b) shows data to you (c) stores data online (d) measures the real world
23. 23.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
24. 24.🔍 Which is the odd one out? (a) a buzzer (b) a siren (c) a loudspeaker (d) a traffic signal
25. 25.True or false: the ammeter measures voltage. (a) True (b) False
26. 26.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
27. 27.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 260 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.True or false: to use a cable with cuts is safe. (a) True (b) False
29. 29.Which of these is a risky habit? (a) share only needed data (b) keep factory passwords (c) set up with a parent (d) set a strong password
30. 30.📏 How many ohms (Ω) is 8 kΩ?
31. 31.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
32. 32.True or false: a motor turns a fan or wheels. (a) True (b) False
33. 33.⚡ What does an LED lamp mainly change electricity into? (a) light (b) movement (c) sound (d) heat
34. 34.Which of these mainly makes movement? (a) a ceiling fan (b) a siren (c) a street light (d) a rice cooker
35. 35.🔘 When a switch is ON, the circuit is … (a) cut (b) open (c) broken (d) closed
36. 36.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets bigger (d) gets smaller
37. 37.Which of these is the input? (a) the pump turns on (b) an LED lights up (c) compare with a limit (d) a temperature reading
38. 38.🤖 When the main loop of a microcontroller program ends, what happens? (a) it starts again (b) the board breaks (c) it deletes itself (d) it stops forever
39. 39.Which of these is an insulator? (a) an iron nail (b) a metal paper clip (c) a glass marble (d) a steel spoon
40. 40.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?

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