Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 615 · 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.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
2. 2.Which of these is true of a series circuit? (a) each gets the full volts (b) a single current path (c) one out, the rest glow (d) many paths for current
3. 3.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
4. 4.True or false: a microcontroller uses very little power. (a) False (b) True
5. 5.🔁 x = 3
   repeat 1 time { x = x × 2 }
   What is x at the end?
6. 6.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
7. 7.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) less than either one (d) more than either one
9. 9.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a diode (c) a buzzer (d) a resistor
10. 10.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
11. 11.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
12. 12.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
13. 13.⏱️ loop forever { LED ON; wait 700 ms; LED OFF; wait 150 ms }
    How many milliseconds does one blink (ON + OFF) take?
14. 14.Which job needs a sound sensor? (a) spot someone walking in (b) water a dry plant (c) make a parking alarm (d) switch on with a clap
15. 15.🔺 A current of 0.2 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
16. 16.⚙️ Which actuator would you use to turn to an exact angle? (a) a servo motor (b) a motor (c) a buzzer (d) a display
17. 17.📏 How many kilowatts (kW) is 1800 W? =
18. 18.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the loop is complete (d) a wire is cut
19. 19.📏 How many milliamperes (mA) is 0.91 A?
20. 20.Which of these is a good habit? (a) share camera links (b) reuse one password (c) read app permissions (d) accept every permission
21. 21.🧭 Which part of a microcontroller board brings power and code? (a) the pins (b) the USB port (c) the voltage regulator (d) the reset button
22. 22.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a buzzer (b) a motor (c) an LED (d) a servo motor
23. 23.🔍 Which is the odd one out? (a) use LED lamps (b) use old filament bulbs (c) set the AC to 24 °C (d) switch off empty rooms
24. 24.Which of these is an IoT device? (a) a pencil sharpener (b) a Wi-Fi smart plug (c) a battery torch (d) a wind-up clock
25. 25.🔍 An object is 272 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
26. 26.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 950 ms }
    How many milliseconds does one blink (ON + OFF) take?
27. 27.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the if part (c) the else part (d) both parts
28. 28.What does an LED do? (a) stores a little charge (b) is a resistance knob (c) makes things spin (d) glows using little power
29. 29.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
30. 30.🌈 A resistor has the colour bands blue, blue, black. What is its value (in ohms)?
31. 31.🔁 count = 10
    repeat 10 times { count = count + 2 }
    What is count at the end?
32. 32.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is OFF. Does the bulb glow? (a) Yes (b) No
33. 33.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only A is true (c) only B is true (d) both are false
34. 34.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) so all go off together (d) each gets full voltage
35. 35.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 2 and 3 are taken out of their holders. How many bulbs glow?
36. 36.⚡ What does an electric kettle mainly change electricity into? (a) light (b) movement (c) heat (d) sound
37. 37.Which job needs a rain sensor? (a) make a parking alarm (b) keep an incubator warm (c) close a window in rain (d) start a fan when hot
38. 38.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) it is sent by Wi-Fi (b) the app shows it (c) the board reads it (d) the cloud stores it
39. 39.🔍 Which sensor would you use to warn of a gas leak? (a) a motion sensor (b) a rain sensor (c) a light sensor (d) a gas sensor
40. 40.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?

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