Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 763 · 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.🔐 Is it a good or a risky habit to install software updates? (a) risky habit (b) good habit
2. 2.Which of these is not safe? (a) stay away from pylons (b) keep drinks far away (c) climb an electric pole (d) use small battery cells
3. 3.🌈 Which band is read first on a resistor? (a) the widest gap (b) any band (c) the gold band (d) the one nearest an end
4. 4.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
5. 5.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) the same voltage (d) no voltage
6. 6.🧩 Which component turns a fan or wheels? (a) LED (b) resistor (c) buzzer (d) motor
7. 7.Which of these is not safe? (a) keep drinks far away (b) stop if a part gets hot (c) dry your hands first (d) use mains for a project
8. 8.True or false: a dry cork is a conductor. (a) False (b) True
9. 9.🔍 A distance sensor sends a sound pulse and hears the echo 1 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
10. 10.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a resistor (d) a diode
11. 11.Which of these is a risky habit? (a) log out of shared phones (b) read app permissions (c) post your live location (d) change default passwords
12. 12.🔘 Which kind of switch slides side to side? (a) a push button (b) a toggle switch (c) a tilt switch (d) a slide switch
13. 13.🔍 An object is 238 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
14. 14.Which of these is the output? (a) compare with a limit (b) a temperature reading (c) an LED lights up (d) a button press
15. 15.🔘 Which kind of switch stays where you flip it? (a) a toggle switch (b) a tilt switch (c) a push button (d) a reed switch
16. 16.True or false: “many paths for current” is true of a series circuit. (a) False (b) True
17. 17.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 400 ms }
    How many times does the LED blink in 3 seconds?
18. 18.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an input (d) an output
19. 19.📶 Digital or analog: how loud a sound is? (a) digital (b) analog
20. 20.🔘 When a switch is ON, the circuit is … (a) open (b) closed (c) cut (d) broken
21. 21.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a rubber band. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
23. 23.🔺 A current of 20 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
24. 24.🌐 In an IoT system, which part stores data online? (a) phone app (b) Wi-Fi (c) microcontroller (d) cloud server
25. 25.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 38 °C. What is shown? (a) Hot (b) Cool (c) Warm
26. 26.🔁 count = 0
    repeat 4 times { count = count + 10 }
    What is count at the end?
27. 27.🔍 Which is the odd one out? (a) a plain wall switch (b) a Wi-Fi smart plug (c) a battery torch (d) a paper calendar
28. 28.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) compare with the limit (b) wait a few seconds (c) switch the pump on/off (d) read the soil sensor
29. 29.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) diode (b) cell (c) battery (d) junction
30. 30.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V + I (c) R = V ÷ I (d) R = I ÷ V
31. 31.What does a tilt switch do? (a) springs back when let go (b) works only while pressed (c) flips up or down (d) closes when tipped over
32. 32.🔐 Is it a good or a risky habit to tap unknown app links? (a) good habit (b) risky habit
33. 33.True or false: a toy robot has no microcontroller inside. (a) False (b) True
34. 34.True or false: to close a window in rain, use a rain sensor. (a) False (b) True
35. 35.Which of these is the input? (a) count button presses (b) a temperature reading (c) compare with a limit (d) decide if soil is dry
36. 36.True or false: to use a cable with cuts is not safe. (a) True (b) False
37. 37.Which of these is not safe? (a) stop if a part gets hot (b) take cells out after use (c) fly a kite near wires (d) fly kites in open fields
38. 38.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) stays the same (c) gets bigger (d) becomes zero
39. 39.🧮 A 470 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
40. 40.🔺 A current of 0.25 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?

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