Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 520 · 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.True or false: to share camera links is a risky habit. (a) False (b) True
2. 2.Which of these is not safe? (a) touch a switch when wet (b) take cells out after use (c) stop if a part gets hot (d) fly kites in open fields
3. 3.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
4. 4.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) the longer line (c) neither line (d) both lines
5. 5.🔁 count = 2
   while (count < 34) { count = count + 4 }
   How many times does the loop run?
6. 6.Which drawing is the symbol for an ammeter? (a) many long-short pairs (b) a long and a short line (c) a circle with A inside (d) two or more cell symbols
7. 7.True or false: a resistor senses how bright it is. (a) False (b) True
8. 8.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 3 hours?
9. 9.Which job needs a distance sensor? (a) open blinds at sunrise (b) stop a robot near walls (c) close a window in rain (d) spot someone walking in
10. 10.💡 What does LED stand for? (a) light-emitting diode (b) low energy device (c) light energy dial (d) large electric dial
11. 11.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 14 °C. What is shown? (a) Hot (b) Cool (c) Warm
12. 12.Which of these is true of a series circuit? (a) own switch for each bulb (b) each gets the full volts (c) one out, the rest glow (d) a single current path
13. 13.🌈 A resistor has the colour bands grey, black, red. What is its value in kilo-ohms (kΩ)? =
14. 14.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
15. 15.🔘 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?
16. 16.🌈 In the resistor colour code, which number does brown stand for?
17. 17.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
18. 18.🔁 What does a variable do in a program? (a) blinks an LED (b) joins two wires (c) measures light (d) stores a value
19. 19.⚡ What does a siren mainly change electricity into? (a) movement (b) sound (c) light (d) heat
20. 20.Which of these is safe? (a) poke things in a socket (b) climb an electric pole (c) use small battery cells (d) use mains for a project
21. 21.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) spin a wheel (d) make light
22. 22.📏 How many milliamperes (mA) is 0.41 A?
23. 23.🔍 Which is the odd one out? (a) use a cable with cuts (b) touch a switch when wet (c) dry your hands first (d) climb an electric pole
24. 24.True or false: to turn off unused gadgets is a good habit. (a) False (b) True
25. 25.🔺 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
26. 26.🔍 Which sensor would you use to spot someone walking in? (a) a rain sensor (b) a distance sensor (c) a motion sensor (d) a light sensor
27. 27.Which of these saves electricity? (a) leave fridge door open (b) unplug idle chargers (c) iron one shirt at a time (d) run fans in empty rooms
28. 28.⚡ What does an electric iron mainly change electricity into? (a) light (b) sound (c) heat (d) movement
29. 29.🔁 count = 8
    repeat 2 times { count = count + 3 }
    What is count at the end?
30. 30.🔍 Which is the odd one out? (a) log out of shared phones (b) turn off unused gadgets (c) share the Wi-Fi key (d) read app permissions
31. 31.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2200 Ω resistor? (a) red-orange-red (b) red-red-orange (c) red-red-brown (d) red-red-red
32. 32.🔘 What does a switch do in a circuit? (a) stores current (b) opens or closes the loop (c) changes the voltage (d) makes electricity
33. 33.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) voltmeter (b) diode (c) junction (d) switch
34. 34.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) a single current path (c) bulbs share the voltage (d) one out, the rest glow
35. 35.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) to make bulbs dim (d) so all go off together
36. 36.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
37. 37.🔁 x = 1
    repeat 3 times { x = x × 2 }
    What is x at the end?
38. 38.True or false: a wooden stick is a conductor. (a) True (b) False
39. 39.🌈 A resistor has the colour bands green, green, orange. What is its value in kilo-ohms (kΩ)? =
40. 40.🔺 An 18.8 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?

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