Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 887 · 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.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a copper wire across the gap. Does the bulb glow? (a) Yes (b) No
2. 2.🔍 Which is the odd one out? (a) accept every permission (b) tap unknown app links (c) log out of shared phones (d) share camera links
3. 3.🔍 Which sensor would you use to open blinds at sunrise? (a) a soil moisture sensor (b) a light sensor (c) a motion sensor (d) a gas sensor
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 47 Ω resistor? (a) violet-yellow-black (b) yellow-violet-brown (c) green-violet-black (d) yellow-violet-black
5. 5.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 70 Ω resistor? (a) grey-violet-black (b) grey-black-black (c) violet-black-black (d) violet-black-brown
6. 6.🌈 A resistor has the colour bands green, green, brown. What is its value (in ohms)?
7. 7.🤖 if (temperature > 30) { fan ON } else { fan OFF }
   The temperature sensor reads 35 °C. What happens? (a) fan ON (b) fan OFF
8. 8.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
9. 9.📏 How many amperes (A) is 1590 mA? =
10. 10.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) an LED (d) a motor
11. 11.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a bulb (d) a long wire
12. 12.True or false: a thermistor glows using little power. (a) False (b) True
13. 13.Which of these is the output? (a) compare with a limit (b) the fan starts (c) count button presses (d) a motion sensor signal
14. 14.Which of these mainly gives out heat? (a) an electric toy car (b) a buzzer (c) an electric kettle (d) a ceiling fan
15. 15.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
16. 16.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
17. 17.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
18. 18.Which job is done by the pins? (a) runs the program (b) brings power and code (c) restarts the program (d) connect sensors and LEDs
19. 19.Which of these is an output? (a) a buzzer (b) a keypad (c) a sound sensor (d) a temperature sensor
20. 20.💡 A red LED uses 2 V and should get 20 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
21. 21.🔌 Is a motor an input or an output for a microcontroller? (a) output (b) input
22. 22.True or false: to dry your hands first is not safe. (a) True (b) False
23. 23.🔍 Which is the odd one out? (a) a glass marble (b) a metal paper clip (c) a steel coin (d) a safety pin
24. 24.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 25 % (d) 5 %
25. 25.True or false: to keep an incubator warm, use a light sensor. (a) True (b) False
26. 26.🔁 x = 5
    repeat 5 times { x = x × 2 }
    What is x at the end?
27. 27.True or false: to climb an electric pole is not safe. (a) False (b) True
28. 28.🌐 In an IoT system, which part reads values, decides? (a) sensor (b) Wi-Fi (c) microcontroller (d) actuator
29. 29.What does a toggle switch do? (a) slides side to side (b) works only while pressed (c) stays where you flip it (d) closes when tipped over
30. 30.Which of these mainly makes movement? (a) an electric toy car (b) a rice cooker (c) a school bell (d) a buzzer
31. 31.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) an oil lamp (d) a candle
32. 32.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
33. 33.🔘 Which kind of switch springs back when let go? (a) a push button (b) a tilt switch (c) a toggle switch (d) a slide switch
34. 34.🔘 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 OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
35. 35.What does a slide switch do? (a) closes when tipped over (b) slides side to side (c) closes near a magnet (d) flips up or down
36. 36.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
37. 37.🔺 A 0.5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
38. 38.🔋 5 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
39. 39.Which of these is safe? (a) poke things in a socket (b) use mains for a project (c) take cells out after use (d) touch a switch when wet
40. 40.Which of these mainly gives out light? (a) a street light (b) a toaster (c) a siren (d) an exhaust fan

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