Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 377 · 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: a brass key is a conductor. (a) False (b) True
2. 2.True or false: a buzzer mainly makes sound. (a) False (b) True
3. 3.🔺 A current of 0.2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 5 % (c) 25 % (d) 50 %
6. 6.Which of these is an input? (a) a servo motor (b) an LED (c) a small display (d) a light sensor
7. 7.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 67 Ω resistor? (a) violet-violet-black (b) blue-violet-brown (c) blue-violet-black (d) violet-blue-black
8. 8.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
9. 9.🧮 Resistors of 47 Ω, 150 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
10. 10.True or false: to share only needed data is a risky habit. (a) False (b) True
11. 11.Which job needs a buzzer? (a) show the temperature (b) open a gate to 90° (c) show a status light (d) beep an alarm
12. 12.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) joins two wires (d) blinks an LED
13. 13.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
14. 14.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) the switch is ON (d) all wires are joined
15. 15.🧮 A 3.2 V battery is joined to 12 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
16. 16.⚡ What do we call a flow of electric charge through a wire? (a) a magnet (b) electric current (c) sound (d) friction
17. 17.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V × I (d) P = V + I
18. 18.Which of these is the input? (a) compare with a limit (b) decide if soil is dry (c) check if temp > 30 (d) a temperature reading
19. 19.🔺 A current of 3 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
20. 20.Which job is done by the main chip? (a) runs the program (b) keeps the voltage steady (c) restarts the program (d) connect sensors and LEDs
21. 21.⚡ A device works on 3 V and takes 0.5 A. What is its power (in watts)? =
22. 22.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
23. 23.Which of these is the process? (a) a temperature reading (b) a button press (c) a light level reading (d) decide if soil is dry
24. 24.🔍 Which is the odd one out? (a) aluminium foil (b) a wooden stick (c) a woollen thread (d) a plastic ruler
25. 25.🔢 To plan an electronics project, which is the LAST step? (a) draw the circuit diagram (b) test it and fix it (c) pick a problem to solve (d) list inputs and outputs
26. 26.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 20000 Ω resistor? (a) orange-red-orange (b) red-black-red (c) red-black-orange (d) red-black-yellow
27. 27.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 25 °C. What is shown? (a) Warm (b) Hot (c) Cool
28. 28.🔢 To get a sensor reading onto a phone, which comes first: “the cloud stores it” or “the app shows it”? (a) the app shows it (b) the cloud stores it
29. 29.What does a push button do? (a) stays where you flip it (b) works only while pressed (c) closes when tipped over (d) closes near a magnet
30. 30.True or false: the voltmeter is joined across a part. (a) False (b) True
31. 31.Which of these is a good habit? (a) set up with a parent (b) share camera links (c) tap unknown app links (d) reuse one password
32. 32.🔋 A 6 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
33. 33.🔍 Which is the odd one out? (a) a cotton thread (b) a steel spoon (c) a copper wire (d) a graphite rod
34. 34.🔌 Is a keypad an input or an output for a microcontroller? (a) output (b) input
35. 35.Which drawing is the symbol for a capacitor? (a) a straight line (b) a small empty box (c) two equal parallel lines (d) triangle against a bar
36. 36.Which of these is a good habit? (a) post your live location (b) keep factory passwords (c) share camera links (d) read app permissions
37. 37.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
38. 38.Which of these is safe? (a) poke things in a socket (b) fly kites in open fields (c) touch a switch when wet (d) open a phone charger
39. 39.🔌 A gap of dry air between two wires acts as … (a) a conductor (b) a switch that is ON (c) a cell (d) an insulator
40. 40.True or false: a push button springs back when let go. (a) True (b) False

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