Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 711 · 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 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
2. 2.⚡ What does a tube light mainly change electricity into? (a) light (b) sound (c) movement (d) heat
3. 3.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
4. 4.🔺 A current of 10 mA flows when 4.7 V is joined across a resistor. What is its resistance (in ohms)?
5. 5.What does a potentiometer do? (a) turns a fan or wheels (b) glows using little power (c) limits the current (d) is a resistance knob
6. 6.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
7. 7.🌈 In the resistor colour code, which number does orange stand for?
8. 8.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I ÷ R (d) V = I + R
10. 10.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) water makes it cold (c) it spoils the paint (d) water carries current
11. 11.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) good habit (b) risky habit
12. 12.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
13. 13.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 6.5 V supply. What current flows (in mA)?
14. 14.True or false: to use mains for a project is safe. (a) False (b) True
15. 15.🔁 count = 10
    repeat 8 times { count = count + 7 }
    What is count at the end?
16. 16.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
17. 17.True or false: “decide if soil is dry” is the input. (a) True (b) False
18. 18.🧮 Resistors of 220 Ω, 150 Ω, 50 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
19. 19.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
20. 20.🔺 A current of 0.2 A flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
21. 21.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
22. 22.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a buzzer (b) a motor (c) a servo motor (d) an LED
23. 23.True or false: a candle usually has a microcontroller inside. (a) True (b) False
24. 24.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
25. 25.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
26. 26.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
27. 27.🌈 A resistor has the colour bands orange, black, orange. What is its value in kilo-ohms (kΩ)? =
28. 28.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
29. 29.🔁 count = 1
    while (count < 29) { count = count + 4 }
    How many times does the loop run?
30. 30.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 648. What happens? (a) lamp ON (b) lamp OFF
31. 31.🔺 A current of 20 mA flows when 6.6 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) a break stops every bulb (d) many paths for current
33. 33.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V ÷ R (d) I = V × R
34. 34.🔍 Which is the odd one out? (a) a graphite rod (b) a copper wire (c) an iron nail (d) a wooden stick
35. 35.⏱️ repeat 10 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
36. 36.🔢 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) read the soil sensor (d) switch the pump on/off
37. 37.🔍 Which is the odd one out? (a) install software updates (b) share camera links (c) tap unknown app links (d) share the Wi-Fi key
38. 38.True or false: the ammeter is joined across a part. (a) False (b) True
39. 39.🌐 A weather station sends one reading every 15 seconds. How many readings does it send in 9 minutes?
40. 40.💡 3 identical bulbs are joined in parallel across a 1.5 V battery (ideal wires). How many volts does each bulb get? =

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