Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 288 · 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 solar panel changes which kind of energy into electricity? (a) light energy (b) sound energy (c) chemical energy (d) wind energy
2. 2.⚠️ Is it safe to use mains for a project? (a) not safe (b) safe
3. 3.🌈 A resistor has the colour bands yellow, blue, brown. What is its value (in ohms)?
4. 4.True or false: a circle with an X in it is the symbol for a bulb. (a) False (b) True
5. 5.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a smaller voltage (c) the same voltage (d) a bigger voltage
6. 6.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
7. 7.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) wire (b) junction (c) switch (d) bulb
8. 8.🔌 Most metals are good … (a) batteries (b) insulators (c) magnets only (d) conductors
9. 9.🔁 total = 0
   for i = 1 to 5 { total = total + i }
   What is total at the end?
10. 10.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the voltage regulator (c) the power LED (d) the reset button
11. 11.⚠️ Is it safe to throw cells in a fire? (a) safe (b) not safe
12. 12.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
13. 13.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 5 hours?
14. 14.💡 In a series circuit, how many paths does the current have? (a) none (b) one (c) one for each bulb (d) two
15. 15.Which job needs a rain sensor? (a) open blinds at sunrise (b) stop a robot near walls (c) close a window in rain (d) measure classroom noise
16. 16.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
17. 17.🔍 Which is the odd one out? (a) post your live location (b) tap unknown app links (c) share the Wi-Fi key (d) read app permissions
18. 18.🔺 A current of 1.5 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
19. 19.🔋 Does a television give electricity or use electricity? (a) gives electricity (b) uses electricity
20. 20.True or false: a dot where wires meet is the symbol for a battery. (a) True (b) False
21. 21.📏 Which unit measures the flow of charge? (a) volt (V) (b) ampere (A) (c) ohm (Ω) (d) watt (W)
22. 22.🧮 Resistors of 150 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
23. 23.🔺 A 9.4 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
24. 24.💡 An LED is joined to a 9 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
25. 25.📏 How many kilowatts (kW) is 1550 W? =
26. 26.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are ON (c) when both are OFF (d) when either is ON
27. 27.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 4 seconds?
28. 28.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
29. 29.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 330 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
30. 30.True or false: to close the fridge quickly saves electricity. (a) False (b) True
31. 31.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
32. 32.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) the shorter line (c) neither line (d) both lines
33. 33.🔍 Which is the odd one out? (a) take cells out after use (b) fly a kite near wires (c) dry your hands first (d) fly kites in open fields
34. 34.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 400 ms }
    How many milliseconds does one blink (ON + OFF) take?
35. 35.🔍 Which is the odd one out? (a) a loudspeaker (b) a night lamp (c) a traffic signal (d) an LED lamp
36. 36.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
37. 37.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
38. 38.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
39. 39.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False
40. 40.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?

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