Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 716 · 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 sensor would you use to open blinds at sunrise? (a) a light sensor (b) a soil moisture sensor (c) a distance sensor (d) a gas sensor
2. 2.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
3. 3.⚡ A device works on 9 V and takes 0.1 A. What is its power (in watts)? =
4. 4.🔁 total = 0
   for i = 1 to 8 { total = total + i }
   What is total at the end?
5. 5.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
6. 6.Which job needs a sound sensor? (a) spot someone walking in (b) measure classroom noise (c) warn of a gas leak (d) switch on lamps at dusk
7. 7.True or false: two equal parallel lines is the symbol for a bulb. (a) True (b) False
8. 8.True or false: “a knob turned part way” is a digital signal. (a) True (b) False
9. 9.True or false: to read app permissions is a good habit. (a) False (b) True
10. 10.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V × I (d) P = V + I
11. 11.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) No (b) Yes
12. 12.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the if part (c) both parts (d) the else part
13. 13.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
14. 14.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 40000 Ω resistor? (a) yellow-black-red (b) yellow-black-orange (c) green-yellow-orange (d) yellow-black-yellow
15. 15.🔍 Which sensor would you use to keep an incubator warm? (a) a light sensor (b) a gas sensor (c) a temperature sensor (d) a sound sensor
16. 16.📏 How many kilowatts (kW) is 3050 W? =
17. 17.True or false: the voltmeter measures voltage. (a) False (b) True
18. 18.📏 How many kilo-ohms (kΩ) is 300 Ω? =
19. 19.Which job is done by the voltage regulator? (a) brings power and code (b) runs the program (c) keeps the voltage steady (d) shows the board is on
20. 20.🔁 count = 2
    while (count < 17) { count = count + 3 }
    How many times does the loop run?
21. 21.🌈 In the resistor colour code, which number does black stand for?
22. 22.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
23. 23.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
24. 24.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they explode (c) they get dimmer (d) they all go out
25. 25.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
26. 26.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
27. 27.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🤖 What is a microcontroller? (a) a kind of bulb (b) a computer on one chip (c) a big desktop computer (d) a type of battery
29. 29.Which of these is safe? (a) climb an electric pole (b) fly a kite near wires (c) touch a fallen wire (d) stop if a part gets hot
30. 30.🔘 A bulb and a cell are joined through 2 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
31. 31.🔺 A current of 1.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🔍 Which is the odd one out? (a) a sound sensor (b) a keypad (c) a turning knob (d) an LED
33. 33.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
34. 34.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
35. 35.True or false: a dry cork is an insulator. (a) True (b) False
36. 36.What does a potentiometer do? (a) is a resistance knob (b) makes a beeping sound (c) blows if current is high (d) beeps for an alarm
37. 37.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) compare with the limit (b) wait a few seconds (c) read the soil sensor
38. 38.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) a single current path (c) one bulb out, all go out (d) each gets the full volts
39. 39.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) No (b) Yes
40. 40.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel

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