Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 778 · 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 gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
2. 2.🌈 A resistor has the colour bands yellow, white, black. What is its value (in ohms)?
3. 3.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
4. 4.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
5. 5.🔋 How many 1.5 V cells must be joined in series to give 12 V?
6. 6.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) share it with friends (c) type it all in (d) ask a parent first
7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the glass (d) the filament
8. 8.Which of these gives us electricity? (a) a mobile phone (b) a refrigerator (c) a solar panel (d) an air conditioner
9. 9.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
10. 10.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the plastic handle (c) the metal tip (d) the bare end
11. 11.🧩 Which component has coloured bands? (a) resistor (b) LDR (c) potentiometer (d) transistor
12. 12.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 1000 (d) 60
13. 13.Which of these is an insulator? (a) a steel spoon (b) a rubber eraser (c) aluminium foil (d) a graphite rod
14. 14.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.💡 6 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
16. 16.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
17. 17.🔍 Which is the odd one out? (a) install software updates (b) turn off unused gadgets (c) set a strong password (d) tap unknown app links
18. 18.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) the box colour (c) inputs and outputs (d) the final price
19. 19.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) neither line (d) the longer line
20. 20.🔁 count = 4
    while (count < 24) { count = count + 4 }
    How many times does the loop run?
21. 21.What does a reed switch do? (a) springs back when let go (b) closes near a magnet (c) flips up or down (d) slides side to side
22. 22.🔺 A 30 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
23. 23.🔌 Is a buzzer an input or an output for a microcontroller? (a) output (b) input
24. 24.True or false: “a single current path” is true of a series circuit. (a) False (b) True
25. 25.📏 Which unit measures the flow of charge? (a) ohm (Ω) (b) watt (W) (c) ampere (A) (d) volt (V)
26. 26.Which of these is not safe? (a) stop if a part gets hot (b) take cells out after use (c) use mains for a project (d) use small battery cells
27. 27.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) spin a wheel (d) measure heat
28. 28.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 7 seconds?
29. 29.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) water makes it cold (c) it is just untidy (d) water carries current
30. 30.📏 How many milliamperes (mA) is 1.03 A?
31. 31.🔘 When a switch is ON, the circuit is … (a) open (b) broken (c) cut (d) closed
32. 32.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
33. 33.⚡ A solar panel changes which kind of energy into electricity? (a) sound energy (b) wind energy (c) chemical energy (d) light energy
34. 34.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 14 cm. What happens? (a) buzzer beeps (b) buzzer is silent
35. 35.🔌 Is a metal paper clip a conductor or an insulator? (a) an insulator (b) a conductor
36. 36.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
37. 37.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) capacitor (b) resistor (c) battery (d) LED
38. 38.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in 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) Yes (b) No
40. 40.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) input (b) output

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