Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 447 · 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: on an LED, the longer leg is the cathode (−). (a) False (b) True
2. 2.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 310 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
3. 3.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
4. 4.🔌 Is a wooden stick a conductor or an insulator? (a) a conductor (b) an insulator
5. 5.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 140 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
6. 6.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 850 ms }
   How many milliseconds does one blink (ON + OFF) take?
7. 7.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the length of a wire (d) the colour of light
8. 8.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
9. 9.🔐 Is it a good or a risky habit to post your live location? (a) risky habit (b) good habit
10. 10.🧮 A 1.8 V battery is joined to 5 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
11. 11.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) waits 500 seconds (d) blinks 500 times
12. 12.💡 An LED is joined to a 6 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) lights up (b) does not light (c) may burn out
13. 13.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the process (b) the input (c) the output (d) the battery
14. 14.What does a resistor do? (a) turns a fan or wheels (b) limits the current (c) beeps for an alarm (d) senses how bright it is
15. 15.🧩 Which component is a resistance knob? (a) diode (b) fuse (c) potentiometer (d) LED
16. 16.🔺 A 5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
17. 17.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 220 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
18. 18.Which of these is a conductor? (a) a graphite rod (b) a glass marble (c) a cotton thread (d) a dry cork
19. 19.True or false: a line lifted at a gap is the symbol for a switch. (a) True (b) False
20. 20.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 250 ms }
    How many milliseconds does one blink (ON + OFF) take?
21. 21.Which of these is not safe? (a) take cells out after use (b) fly a kite near wires (c) fly kites in open fields (d) dry your hands first
22. 22.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
23. 23.⚡ A 5 W device works on 5 V. What current does it take (in amperes)? =
24. 24.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 3000 Ω resistor? (a) orange-black-brown (b) orange-black-orange (c) yellow-orange-red (d) orange-black-red
25. 25.🔍 Which is the odd one out? (a) use small battery cells (b) touch a switch when wet (c) use mains for a project (d) touch a fallen wire
26. 26.🔢 To plan an electronics project, what comes right after “build it with an adult”? (a) draw the circuit diagram (b) list inputs and outputs (c) pick a problem to solve (d) test it and fix it
27. 27.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 1000 (c) 10 (d) 60
28. 28.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
29. 29.🌈 A resistor has the colour bands violet, violet, black. What is its value (in ohms)?
30. 30.🧩 Which component glows using little power? (a) transistor (b) motor (c) LED (d) LDR
31. 31.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) chemical energy (b) sound energy (c) movement energy (d) light energy
32. 32.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 260 Ω resistor? (a) blue-red-brown (b) red-blue-red (c) red-blue-brown (d) red-blue-black
33. 33.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
34. 34.🤖 Which is a safe power source for a beginner microcontroller board? (a) a 230 V cable (b) USB or a 9 V battery (c) a wall socket directly (d) bare mains wires
35. 35.Which of these is the process? (a) the fan starts (b) an alert on the phone (c) count button presses (d) a light level reading
36. 36.🔌 Is a plastic straw a conductor or an insulator? (a) a conductor (b) an insulator
37. 37.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
38. 38.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
39. 39.True or false: aluminium foil is an insulator. (a) False (b) True
40. 40.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?

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